Hire the best Backend Rest API Freelancers in Poland

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$99 hourly
Shiv K.
- 5.0/5
- (51 jobs)
Hello! I am an expert Back-end Developer specializing in FastAPI and Hasura, along with PostgreSQL, MySQL, and MongoDB. My contributions to open-source code include NASA, Tensorflow, Meshtastic, and Python. My job is to turn your awesome ideas into reality as quickly as possible while keeping the backend perfect and the end product stable. I help people build their dream services and solve the problems they encounter with state-of-the-art solutions. Over the last 12 years, I have acquired extensive experience using a variety of languages to craft beautiful back-end systems, along with providing novel solutions, speed optimization, and cloud architecture, ensuring that it can scale globally. I have led the back-end development of ReskyuMe, PaGaLGuY, Easio, and Airbnb amongst many others. An extremely high level of reliability and responsibility is my guarantee, which is evident from all of my reviews being rated 5 stars! I have a deep knowledge of different architectures like x86 and ARM, which allows me to fully understand how different CPUs work, how memory is accessed, and how SIMD/vectorization can be exploited to speed up services. Technologies I use: ✅Languages: C, C++, Python, HTML, CSS, JavaScript ✅Frameworks: FastAPI, Hasura ✅Server Interfaces: REST, GraphQL, Websockets ✅DB Interfaces: SQLAlchemy, SQLModel, PyMongo ✅SQL DBs: PostgreSQL, MySQL, and other SQL-based DBs ✅NoSQL DBs: MongoDB, Cassandra, ScyllaDB ✅Version Control: Git & Mercurial ✅DevOps: Traefik, Nginx, Docker, Kubernetes, Apache, AWS, Google Cloud Platform, Microsoft Azure, Digital Ocean, GitHub Actions ✅Project Management: ClickUp, Trello, Github ✅Operating Sytems: Windows, Linux (Ubuntu, Debian, CentOS, etc.), macOS ✅Cloud Platforms: Amazon Web Services, Google Cloud Platform, Microsoft Azure, DigitalOcean, Linode, Hostinger, et al ✅Cloud Services: Cloudflare ✅LLMs: ChatGPT and self-hosted ones Vast knowledge of: ✅Software design and development ✅Different hardware platforms: x86 and ARM ✅Parallel processing: SIMD and Vectorization ✅Cloud Architecture, CI/CD ✅SQL query construction ✅NoSQL query construction ✅Object-Oriented Programming ✅Speed optimization ✅Usability ✅Security

Backend Rest API
Cloud Engineering
Cloud Architecture
Cloudflare
SQLAlchemy
Object-Oriented Programming
Database Optimization
Performance Optimization
Multithreaded, Parallel, & Distributed Programming Language
Azure DevOps
Docker
RESTful API
MySQL
GraphQL
PostgreSQL
Python
$40 hourly
Robert B.
- 5.0/5
- (5 jobs)
Full-Stack .NET developer with 5 years of experience. Experienced developer specializing in crafting websites and services for medium to large enterprises. My expertise lies in .NET, React, and Azure, with a predominant focus on developing robust integrations and automations. Understanding the importance of clear communication, I actively engage with clients to set realistic milestones and expectations, ensuring high-quality outcomes and satisfied partnerships.

Backend Rest API
.NET Core
API
Web Services Development
Web Service
Microsoft Azure
RESTful API
Microservice
Web Application
React
.NET Framework
$25 hourly
Hussein M.
- 5.0/5
- (3 jobs)
Full-Stack Developer with 5+ Years of Experience Dynamic and versatile developer specializing in building high-performance, secure, and scalable mobile and web applications. Adept at bridging the gap between backend architecture and frontend functionality to deliver seamless, intuitive user experiences. Technical Expertise: Backend Development: Extensive experience in developing and optimizing robust backend architectures using Python, Node.js, and modern frameworks. Proficient in designing RESTful APIs and GraphQL endpoints for efficient data exchange. AI & LLM Integration: Skilled in integrating Large Language Models (LLMs) and AI technologies to power intelligent application features, enhance user interactions, and optimize business workflows. Cloud Infrastructure: Expertise in deploying and managing cloud environments, including AWS (EC2, Lambda, S3, RDS) and Azure. Experience setting up scalable microservices, serverless architecture, and containerized solutions with Docker and Kubernetes. Security & Encryption: Strong focus on backend security, implementing advanced encryption protocols, secure authentication mechanisms (OAuth 2.0, JWT), and data protection strategies to safeguard applications. Database Management: Proficient in relational databases (PostgreSQL, MySQL) and NoSQL databases (MongoDB, DynamoDB) to handle complex, scalable data storage needs. Modern Development Practices: Leveraging GitOps, CI/CD pipelines, and automated testing frameworks to streamline development and deployment cycles. AI-Driven Efficiency & Team Leadership: Embraces cutting-edge AI tools to enhance productivity, reduce development time by up to 50%, and ensure error-free code deployment. Implements AI-driven team automation solutions to optimize workflows, manage projects effectively, and foster a collaborative environment. Utilizes AI-powered code assistants and analytics tools to expedite debugging, enhance code quality, and meet tight deadlines with precision. Full-Stack & Cross-Platform Expertise: Combines backend proficiency with frontend capabilities, leveraging frameworks like Flutter, React, and Angular to deliver visually stunning, responsive applications. Skilled in integrating APIs, third-party services, and payment gateways, ensuring comprehensive functionality across platforms.

Backend Rest API
RESTful API
Python
Encryption
Agile Software Development
UI/UX Prototyping
Mobile App Development
Flutter
Android
iOS
Web Application
Full-Stack Development
Product Management
$29 hourly
Nazar R.
- 5.0/5
- (7 jobs)
I'm a Senior Full Stack Developer with 10+ years of experience in Full Stack development. 🏆 Certified Senior Full Stack Developer in React.js, Node.js, Next.js, Nest.js, ExpressJS 🏆 Top Rated Upwork Full Stack Developer React Node.js 💎 10+ Years of commercial experience as a Full Stack Developer 🏆 20+ Successfully finished projects on Upwork with 5 stars feedback 🕒 1500+ Total Working Hours on Upwork 🏆 Master's Degree in Computer Science I can provide development services: 💎 As Front End Developer - Creating responsive and user-friendly interfaces on React and Next.js. 💎 As Back End Developer - Building robust and scalable server-side applications and APIs on Node.js. It also could be NestJS backend or ExpressJS backend as I'm NestJS developer and Express JS developer, too 💎 As Full Stack Developer - Providing comprehensive solutions covering both front-end and back-end development, also working with MERN stack. Skills & Expertise: 🛠 Front-End Development - React, Next.js 🛠 Back-End Development - Node.js, Nest.js, Express.js 🛠 Database - MongoDB, Firebase, MySQL, PostgreSQL, Supabase 🛠 Programming Languages - JavaScript, TypeScript 🛠 Communication - RESTful APIs, GraphQL, WebSockets 🛠 Design Tools - Figma, Adobe XD, Sketch 🛠 Version Control - Git & GitHub & GitLab & Bitbucket 🛠 CI/CD - Jenkins GitLab CI 🛠 Project Management - Jira, Trello, Asana, Notion 🛠 Testing Frameworks - Jest, Mocha, Unit testing 🛠 Libraries - Bootstrap, Moment.js, Redux, Redux-toolkit, Redux-saga, Material-UI, React-query, Axios, Sequelize, TypeORM, Socket.IO, JsonWebToken, Formik, React Hook Fosm, ANTD, Storybook, Highcharts, RxJs; Tailwind CSS; React Twilio Why My Full Stack Development Solutions Stand Out:  📍 100+ successfully finished projects: SaaS solutions, Web applications (web apps), websites, landing pages, PWA, SPA, Admin Panels, CRM, ERP, E-commerce marketplaces, IoT, Proof of Concept (POC), MVP, machine learning, Booking platforms, Shopify apps, E-learning platforms, Finance apps, chatbot development, Stock trading app for day trading and others. 📍 Proven experience in domains: E-commerce, Healthcare, Real Estate, Education, Fintech, AI solutions, Management, Travel and Hospitality. 📍 Successfully integrated WebSockets, RESTful APIs, and third-party APIs such as: Stripe API, Zoom API, OpenAI API, ChatGPT, shopify plugin, capacitor vue, wordpress speed. 📍 Have proven experience with such authorization services: OAuth, JWT, OAuth2, Web Tokens As A Result, My Clients Got The Next Benefits: ✅ +20% Efficiency Increase: My work helps projects be delivered faster using streamline workflow and agile methods. I write code efficiently so products reach the market quickly. ✅ +30% User Engagement Enhance: My designs and responsive interfaces attract users and make them interact more, which leads to higher satisfaction and conversion rates that grow business. ✅ 100% Scalability & Performance: I build systems that can handle heavy traffic with fast performance and very little downtime. This supports your business operation success. ✅ 100% Custom Fit Solutions: I create tailor-made solutions that match each client's business needs, resulting in real improvements in productivity and ROI. ✅ 15% Cost Saving: By optimizing code and infrastructure, my solution reduces long-term maintenance costs and resource expenses, saving money for business. 🏆 As an Expert in Full Stack development, I have experience working as: React Developer, Front end Developer, Back end Developer, Full-Stack developer, Full Stack React Developer, JavaScript Developer, React JS Developer, React Web Developer, Nest.js developer, MERN Stack developer, Software developer, Web developer, SaaS developer, Full Stack developer React, Next.js Developer, Node.js Developer, WordPress developer, React Native developer, Mobile App developer, Python rest api developer, Python developer, Java developer, Python NodeJS developer, React Native Full Stack developer and DBA, SaaS marketing adviser, front end WordPress, Full Stack Web developer, API developer, JavaScript Developer, Senior React and Node Developer Also, helped with UX UI web design as a ui ux designer. Have experience working with: angular, laravel, ruby on rails, spring framework. As an Expert Full Stack Developer and CEO of a Development company, I'm ready to elevate your project to new heights of success! 🚀🚀🚀

Backend Rest API
AI Development
Full-Stack Development
API
API Development
Tailwind CSS
Next.js
ExpressJS
RESTful API
Web Development
JavaScript
TypeScript
MongoDB
Node.js
React
$30 hourly
Anass H.
- 5.0/5
- (35 jobs)
Highly experienced and Friendly Full Stack Developer. Offering professional services and consultations in the field of web development. Proficient in utilizing a variety of PHP based frameworks Symfony & Laravel Programming Languages & Frameworks: PHP (Symfony, Laravel and CodeIgniter) Javascript (React, Vue.js), Python (Django, Flask), FE Frameworks (Tailwind, Bootstrap and Materialize) RDBMSes: MySQL , MSSQL and PostgreSQL Operating Systems: Debian, Ubuntu and CentOS. (incl. Containerization with Docker) Graphics and Animation: Photoshop, Illustrator and After Effects.

Backend Rest API
Linux System Administration
Graphic Design
Object-Oriented Programming
RESTful API
Django
Python
MySQL
React
CSS 3
HTML5
JavaScript
Web Development
Symfony
Laravel
PHP
$80 hourly
Nikita P.
- 5.0/5
- (10 jobs)
Greetings! 🏆 100% Job Success | ⌛600+ hours on UpWork | 💎 Top Rated Plus Freelancer 👨🏻‍💻 8+ years of experience | Senior Front-End Engineer ⭐ Expert: Next.js | React.js | JavaScript | TailwindCSS | HTML | CSS | ChatGPT | v0.dev ✅ Daily updates, ✅ Flexible Availability, ✅ Highest-Quality deliverables ⭐ What I can bring to your project ⭐ ✅ Website or Complex Web Application Development ✅ Top-notch knowledge of React, JavaScript, TypeScript, Redux ✅ Advanced understanding of UI Architectures and what works best for your project ✅ Optimization techniques for efficiently solving bottlenecks in your project ✅ Extensive experience with building Complex UI Solutions and Web Applications ✅ Clean code that conforms to best engineering practices ✅ Ability to quickly diagnose existing code bases and find ways to improve them ✅ You will always be aware of the project status with the help of my task management tools ⭐ Why you should choose me over other freelancers ⭐ ✅ Trust: I'm always transparent about my processes ✅ Ownership: I focus on providing value to your business and maintain impeccable agreements ✅ WOW Factor: this is core to my work as a freelancer. I strive to give more than what I receive to ultimately make you happy about working with me and choosing to hire me again ✅ Problem-solver: I never give up until I find a good solution. I solve problems. ✅ Genuine: I'm rooting for your success. It makes both human and business sense - knowing I've helped you succeed, you'll return to purchase more of my services! ✅ Someone who cares about helping you succeed and bringing value to your business But don't just take my word for it: ⭐⭐⭐⭐⭐ ”Nikita is an outstanding full-stack engineer and easily one of the top front-end engineers I've worked with. Here are a few things to call out: - very sharp front-end architecture skills - incredibly high level of ownership - great product sense Our entire team loved working with Nikita, from design to support.” ⭐⭐⭐⭐⭐ ”Nikita was a standout member of our team during his tenure. He took ownership of his work to a whole new level, always going the extra mile to ensure our projects' success. It was clear that he deeply cared about the company and the product, and his dedication showed in the quality of his work. Nikita had a strong grasp of front-end infrastructure, and his technical knowledge was impressive. He kept up with the latest developments in the field and used that knowledge to come up with practical and innovative solutions that benefited our team and clients…” 💻 FRONT-END SKILLS ⭐ Next.js | React ⭐ Redux | Redux Saga ⭐ TypeScript | JavaScript ⭐ HTML | CSS | SCSS ⭐ Jest | React Testing Library ⭐ Webpack ⭐ Babel ⭐ Eslint | Prettier 🧩 UI | COMPONENTS: ⭐ Shadcn UI ⭐ TailwindCSS ⭐ Ant Design ⭐ Material UI ⭐ Styled Components ⭐ HighCharts ⭐ Ag Grid 🎭 ANIMATION ⭐ Framer Motion ⭐ React Three | Three.js 📶 INTEGRATIONS ⭐ Stripe ⭐ Auth0 ⭐ Google Auth ⭐ Segment ⭐ Headway 📐 UI ARCHITECTURE & DESIGN ⭐ Feature-Sliced Design ⭐ Atomic Design 🏁 PAGE SPEED OPTIMIZATION ⭐ Lighthouse ⭐ GMetrix ⭐ Profiler 💻 BACK-END SKILLS: ⭐ Node.js | Express.js ⭐ MongoDB | PostgreSQL ⭐ Mongoose ⭐ REST API ⭐ Docker 🆕 READY TO GET STARTED? NEXT STEPS: 1. Invite me to your job 2. I will send my proposal 3. We'll iron out all the requirements and expectations 4. I'll get the work done professionally to ensure you love the result 5. You'll leave an awesome review at the end 😎

Backend Rest API
TypeScript
Next.js
Tailwind CSS
CSS 3
Web Application
JavaScript
Front-End Development
HTML5
React
Redux
RESTful API
$42 hourly
Stan S.
- 4.6/5
- (22 jobs)
I bring over 9 years of experience helping businesses start with Salesforce and thrive using it. My expertise spans across multiple industries, including recruitment, real estate, e-commerce, finance, insurance, healthcare, and energy. I specialize in tailoring Salesforce solutions that help you achieve your business goals efficiently and effectively. Whether you need a new implementation, custom development, or support for existing projects, I provide a full range of services to elevate your Salesforce instance: My Salesforce Expertise Includes: - Cloud Specialties: Experience Cloud, Service Cloud, Sales Cloud, Marketing Cloud - Custom Development: Lightning Web Components (LWC), Apex, Visualforce, Lightning Aura Framework - Emails Configuration: Email templates, Signatures, DNS/DKIM/SPF configuration (to avoid emails going to spam) - Integrations: REST API integrations (e.g., Make.com, Stripe, Intercom, PayPal, e-commerce platforms, Zoho, Jotforms) - Marketing Automation: Marketing Cloud Email Studio & Automation Studio - User Experience & Security: Setup, Tailoring, Security Management, User Roles & Permissions - Automation: Flows, Workflows, Process Builders - Data Management: Data migration (Salesforce Dataloader), Import & Export (CSV, JSON), Salesforce Data Management Tools - CI/CD & DevOps: Git, Bitbucket, Salesforce Change Sets, Heroku, Azure Salesforce Certifications: - Platform Developer I & II - Security & Privacy Accredited Specialist - Marketing Cloud Email Specialist - Marketing Cloud Admin - Data Cloud Consultant I am passionate about creating Salesforce solutions that make an impact. I prioritize clear communication and a collaborative approach to ensure the success of each project. Let's work together to unlock the full potential of Salesforce for your business.

Backend Rest API
Angular
RESTful API
Visualforce
Salesforce Lightning
Salesforce CRM
React Native
Omnichannel Automation
React
JavaScript
Apex
$80 hourly
Mikita K.
- 5.0/5
- (15 jobs)
🌟 Lead Software Engineer & Data Scientist | Tech Startup Specialist 🎓 MSc Computer Science 🚀 9+ Years Elevating Tech Startups with Advanced Full Stack Development & Data Science At the forefront of tech innovation, I specialize in endless product development, bringing unmatched expertise to robust, scalable solutions. My career spans a series of groundbreaking startups, contributing to multimillion-dollar success stories. My business experience perfectly complement my technical skills, enabling me to align software development with core business goals, market analysis, and efficient team management. 🔑 Core Strengths: * Advanced skills in FastAPI for top-tier API design. * Mastery in data mining and automation with Playwright and Selenium * Deep knowledge in distributed systems, including Kafka and microservices architectures. * Proven excellence in AI and ML, with expertise in TensorFlow and PyTorch. * Proficiency in Cloud Computing with AWS, Azure, DigitalOcean, and GCP. * Expertise in containerization with Docker and Kubernetes (k8s). * Strong knowledge in cybersecurity, ethical hacking, and penetration testing. ✅ Full Stack Development: - Languages: Python, JavaScript, TypeScript, Java, C/C++, Bash; - Python Web Frameworks: FastAPI, Flask, Django, CherryPy, Falcon, Django rest framework, Tornado; - Node.js Web Frameworks: Express.js, Koa.js, Socket.io, Feather.js, Sails.js, Nest.js; - Front-end: React.js, Vue.js; - Databases: MongoDB (GridFS), PostgreSQL, MySQL, MariaDB, Redis, Neo4j, NoSQL; - ORMs: SQLAlchemy, Mongoengine, Marshmallow, Sequelize.js, Mongoose, Prisma; - AMQ: Celery, RabbitMQ; - CI/CD: Docker, docker-compose, kubernetes (k8s); - Deployment: GCP, AWS, MS Azure, DigitalOcean; - SSO: AWS Cognito / Amplify, Auth0, Okta, OneLogin, ORY.sh; - OAuth2.0 OpenID Connect and role management policies: RBAC, ACL, ACP, IAM. 📈 Business Impact: * Contributed to multinational projects for Coca-Cola, Unilever, Sberbank, Bankcolombia, Wargaming; * Recognized in international tech forums, including IAB and Web Summit; 📦 Technical skills: Node.js, Python, Javascript, TypeScript, Java, GoLang, Git, RESTful API, GraphQL, MERN, ES5, ES6, Express, Koa, Feather.js, Sails.js, MongoDB, Redis, DynamoDB, Kafka, MySQL, PostgreSQL, MariaDB, Neo4j, Flask, Django, Selenium, Scrapy, React, React Native, Redux, Vue.js, Webpack, Gulp, Grunt, Pandas, Tensorflow, Keras, NumPy, Docker, Docker-compose, Kubernetes, k8s, Jenkins, Google Cloud Platform, AWS, Microsoft Azure, Cognito, Auth0, Okta, Dialogflow, RASA, Segment, Google Tag Manager, Facebook Pixel, JWT, SQLite, Peewee.

Backend Rest API
Data Engineering
Scrapy
PostgreSQL
ClickHouse
Django
FastAPI
RabbitMQ
Web Scraping
Selenium
Back-End Development
Data Analysis
RESTful API
Full-Stack Development
Node.js
Python
$50 hourly
Seraphim K.
- 4.6/5
- (32 jobs)
Highly skilled and experienced iOS Developer with over 10 years of expertise in designing, developing, and delivering high-performance, user-centric applications for Apple's ecosystem. Proficient in Swift, and the latest Apple frameworks, including SwiftUI, Combine, and ARKit. Adept at leading teams, mentoring developers, and delivering innovative solutions that align with Apple's design principles and ecosystem standards. ✅ Creating pixel-perfect apps with good code style and bugs-free. ✅ Full cycle of mobile app development - from idea to AppStore. ✅ Developed more than 20 iOS applications. ✅ Experienced with all Apple’s operating systems development: iOS, iPadOS, MacOS, WatchOS Apple Development Frameworks: UIKit, SwiftUI, Combine, Core Data, Core Animation ARKit, Core ML, Vision, RealityKit, Metal StoreKit, CloudKit, MapKit, HealthKit Tools & Platforms: Xcode, Instruments, Simulator, TestFlight Git, Fastlane, Jenkins, Firebase App Store Connect, XCTest, Swift Package Manager Architectures & Patterns: MVVM, MVC, VIPER, Coordinator Pattern Proficient in Protocol-Oriented Programming and Functional Programming Third-Party Libraries RxSwift, Alamofire, SnapKit, Realm Additional Expertise Full proficiency in App Store Submission Process Deep understanding of Apple HIG (Human Interface Guidelines) Hands-on experience with CI/CD pipelines for iOS Integration with Apple Pay, iCloud, and other Apple services Building Apple Watch and macOS companion apps Localization and accessibility for global audiences I'm looking forward to your exciting projects of any complexity! Best regards, Seraphim

Backend Rest API
iPhone & iPad Apps
RESTful API
iPad App Development
Mac OS App Development
macOS
Apple Xcode
UIKit
Mobile App Development
Firebase
StoreKit
Core Data
watchOS
iOS Development
Swift
iOS
$50 hourly
Karim A.
- 5.0/5
- (7 jobs)
I have experience in developing complex web applications and creating production environments for them using infrastructure as code. In developing web applications I usually use python and js. I worked with frameworks: Django, Flask, Fast API, Vuejs, React and etc. I use cloud technologies such as AWS, Azure, GCP for product release and testing environments. For configuration I use tools: CloudFormation, Terraform, aws cli, gcloud cli and etc. Also I would like to mention the experience in creating pipelines for building and continuous delivery of code to different environments. I have experience with CI/CD tools like Jenkins, Gitlab CI, Github Actions, Circle CI.

Backend Rest API
DevOps
Vue.js
Amazon Web Services
Terraform
Ansible
Python
Docker
RESTful API
Django
$40 hourly
Andrew Z.
- 5.0/5
- (13 jobs)
Software Engineer with over 3 years of experience🚀Python | Web apps | ETL Pipelines | Chatbots ✅Hire me if you want to talk Tech in Business language. 📌You want to set up a new project? I will propose the best technology stack and Architecture! 📌You have an ongoing project? I will quickly fit in and do my best to support the team and Business goals! 📌You want to refactor your code? I will do a safe transition and make sure nothing is left behind! 💪More about my skills that will help us achieve the best result: ✅Test Driven Development & Domain Driven Design ✅FastAPI, Django/DRF, Flask, Celery, SQLAlchemy ✅Numpy/Pandas, Apache Spark, Apache Airflow ✅ SQLite, MySQL, Microsoft SQL, PostgreSQL, Alembic; ✅ NoSQL - MongoDB, Redis, Elasticsearch; ✅ AWS, Kubernetes 👨‍💻Even more facts about me! 🔸I do tech talks 🔸I held company hiring events 🔸Reach out to know more!

Backend Rest API
Python Asyncio
Linux
Flask
Docker
PostgreSQL
Beautiful Soup
GitHub
NoSQL Database
RESTful API
Django
SQL
Git
Telegram API
MongoDB
Python
$50 hourly
Aliaksander D.
- 5.0/5
- (4 jobs)
DevSecOps engineer with 15 years of experience in cybersecurity, software development and linux administration. Creative, motivated and self driven. I enjoy solving problems and coming up with ideal solutions to them. I managed to work with different technologies and languages where I always relied on performance and effectivity. My main responsibilities: Setting up a logging system Integrated automatical security testing tools for continuous vulnerability management. Hardering linux services using CIS benchmarks Security incidents handling (including malware analysis, external attacks on the infrastructure, attacks on the applications and users). Performed security testing of company's applications Develop security cli tools(please see my github profile) Support and creation of wazuh rules API security Develop rules against phishing attacks Maintaining documentation Code threat assessment Stack of technologies: Ansible, OpenStack, KVM, qemu, virtual networks Wazuh, OpenSearch, Filebeat Nftables, iptables Nmap, masscan, hping, selfdev tools Develop rules against phishing attacks Code review Stack of technologies: Ansible, OpenStack, KVM, qemu, virtual networks Wazuh, OpenSearch, Filebeat Nftables, iptables Nmap, masscan, hping, selfdev tools

Backend Rest API
Automated Testing
Sphinx
Security Engineering
Perl Mojolicious
Linux
Database
MySQL
Docker
Microservice
RESTful API
Kubernetes
Golang
Perl
PostgreSQL
$56 hourly
Firdavs R.
- 4.8/5
- (32 jobs)
Upwork Top 5%. Are you looking for a detail-oriented and meticulous Frontend developer? If so, you are at the right place! Here is what my clients think about me: 💬 "Firdavs was a pleasure to work with, the work was done efficiently and to a great standard. Would definitely work with him again, he is responsible and gets back quickly" 💬 "He’s quick, resilient and technically sound. Felt like we were working with someone from our team. Always available and top-notch work." Key Facts: ✔️ Worked and completed over 100 projects; ✔️ Have plugins and custom themes for sale in marketplaces; ✔️ Expert in Javascript frameworks (React JS/ React Native) ✔️ Over 3 years of solid coding experience. Do you need to build Progressive Web Apps or Single-page applications? I am here to help you! Few things that I can do: ✔️ Creating UI with Next.js and React js; ✔️ Redux, Firebase, Sanity.io, Stripe, Prismic, and other great tools; ✔️ React-router, Material UI, Styled-components, Tailwind; ✔️ Single page applications, Progressive web applications; I can offer you: ✔️ Pixel-perfect web pages ✔️ Building UI with SPAs ✔️ Building whole CRMs from scratch ✔️ Architecturing the whole structure of the website from scratch ✔️ Refactoring old websites and making improvements on the existing applications/projects I achieve high-quality products with a proven software development process. Take a look at my profile and, let's chat!

Backend Rest API
Business with 1-9 Employees
HTML
API
HTML5
XHTML
Material UI
PSD to HTML
JSON
Bootstrap
Git
React
RESTful API
web3.js
CSS
JavaScript
$60 hourly
Bartosz M.
- 5.0/5
- (7 jobs)
Experienced backend Java developer with over a decade of expertise in developing and maintaining high-quality software solutions. My career includes roles at Accenture, Credit Suisse and GFT Group. Based in Poland, I have also worked in London with Luxoft and Unibet, a leading company in the gambling industry. Top-rated Upwork freelancer, ranked in the top 5% of performers with a 100% Job Success Score. Proficient in Java, Spring Boot, REST APIs, and cloud technologies (AWS). Adept at working with distributed international teams, emphasizing clean code practices and delivering challenging projects. Programming Languages: Java, JavaScript, Scala APIs & Integrations: RESTful APIs, GraphQL, WebSocket, RabbitMQ, JMS, Kafka Cloud & DevOps: AWS (Cloudformation), Docker, CI/CD (Jenkins, GitHub Actions) Frameworks & Tools: Spring Framework, Spring Boot, Hibernate, JPA Version Control: Git, GitLab, Bitbucket Databases: MySQL, PostgreSQL, MongoDB, Redis Testing: JUnit, Mockito, Cucumber, TDD Others: Observability, Keycloak, Angular, Maven, Bash

Backend Rest API
CI/CD
Amazon Web Services
Spring MVC
Java Persistence API
Hibernate
API
Spring Boot
RESTful API
SQL
Docker
Web Application
AngularJS
Java
MySQL
Spring Framework
$45 hourly
Maksym D.
- 4.9/5
- (11 jobs)
Hello👋 Are you looking for experienced and certified Java engineers to boost your project? You are on the right page! Clear Solutions team provides Java engineers and grows their skills for you. We have more than 12 years of experience in IT and 8+ in Java. My team and I are happy to provide: 🚀 Java developers with transparent knowledge for transparent rates 🚀 People development services: technical assessments, mentoring, evaluation etc. Based on more than 500 interviews and technical assessments we made in the industry so far we created our own evaluation scale. Therefore you always know what set of knowledge you pay for each grade. Do you feel this is what you need? Let's schedule a quick call and find out how we could help you to grow ✅ I have an experience in the following: 👉 migration from on prem to AWS 👉 building microservce architecture from scratch 👉 delivering robust and high-quality code with unit tests 👉 building java high-load and distributed applications 👉 migration from monolith to microservices 👉 building the right engineering culture inside the company 👉 mentoring technical leaders Tech Stack: 🔹 Languages: Java 8, Java 16, Groovy. Spring boot, RESTful API, DB design, 🔸 Frameworks: Spring, Spring Boot, Hibernate, Spring Data 🔹 Clouds: AWS 🔸 SQL: PostgreSQL, MariaDB, Oracle 🔹 NoSQL: Elasticsearch, Redis, MongoDB, Cassandra, DynamoDB 🔸 Message brockers: Apache Kafka or RabbitMQ 🔹 Testing: Junit5, Testcontainers, Spock, RestAssured We have expertise in the following fields: ✅ FinTech, ✅ Trading, ✅ Cryptocurrency, ✅ Banking, ✅ Data processing, ✅ Healthcare, ✅ Social Networking and more. Do you feel this is what you need? Let's schedule a quick call and find out how we could help you to grow As a Backend Developer, I specialize in building robust Java Applications using Core Java, Spring Framework, and Spring Boot 3, leveraging tools like Maven, Gradle, and Bazel for efficient builds, and integrating Hibernate, JPA, and Apache POI for database and document handling. I have extensive experience with RESTful Architecture and SOAP for designing APIs, ensuring Application Security, and implementing testing frameworks like JUnit, JUnit5, Mochito, and AssertJ. I work across diverse environments, including Docker, AWS, Amazon Elastic Beanstalk, AWS Lambda, Google Cloud, and Azure (Azure Cosmos DB), utilizing databases like PostgreSQL, MySQL, MongoDB, Oracle Database, Microsoft SQL Server, IBM Db2, and RabbitMQ. On the frontend, I use HTML, CSS, JavaScript, TypeScript, Angular, AngularJS, and React, collaborating seamlessly using tools like Jira. For messaging and event-driven architecture, I rely on Apache Kafka, Apache ActiveMQ, and RabbitMQ, and for advanced testing, I employ Testcontainers. With a focus on Software Architecture & Design, I also develop Standalone Applications, Desktop Applications, and Web Services, ensuring scalable, secure solutions for enterprise systems and Microservices Architecture.

Backend Rest API
Amazon Web Services
MySQL
MongoDB
Spring Boot
Kubernetes
RabbitMQ
RESTful API
Elasticsearch
Docker
Hibernate
Spring Framework
Java
SQL
Apache Kafka
$40 hourly
Sergei L.
- 5.0/5
- (8 jobs)
I have 6 years of experience in full-cycle software development, I have worked on developing web, integration, embedded and database applications, and AI technology. The main technologies that I used in my previous projects were Python, Angular, React, SQL, Linux, AWS, Javascript, HTML, CSS, Azure, and Arduino. Methodologies - Scrum, Agile. TECHNOLOGIES FAMILIAR WITH ● Python 3; Python 2; ● Django; Flask; FastAPI; SQLAlchemy, PyQt; ● StableDiffusion, Transformers, Tesseract, Scikit Learn, TensorFlow, NLTK; ● JS; TypeScript; Angular; NodeJS; ReactJS; ● Debian; CentOS; Ubuntu; LinuxMint; ● SQL; PostgreSQL; MySQL; ● MongoDB; ElasticSearch; ● jQuery, Ajax; ● Bootstrap; HTML/CSS; MaterialUI; ● Docker; Kubernetes; ● AWS EC2; AWS S3; AWS Lambda; AWS DynamoDB; ● Azure Cloud; Heroku; Google cloud; ● Bitcoin; Ethereum; Dash; ● Git; My personal qualities - good team player, creativity, brilliant communication skills, constantly learning new.

Backend Rest API
RESTful API
Selenium
jQuery
Flask
Arduino
PyQt
Python
NodeJS Framework
AngularJS
Scrapy
Django
PostgreSQL
AWS Elemental
React
Heroku
$38 hourly
Roman P.
- 5.0/5
- (4 jobs)
⚠️ 𝐏𝐫𝐞𝐬𝐬 𝐈𝐧𝐯𝐢𝐭𝐞 𝐁𝐮𝐭𝐭𝐨𝐧 𝐨𝐧 𝐦𝐲 𝐩𝐚𝐠𝐞 𝐚𝐧𝐝 𝐥𝐞𝐭'𝐬 𝐭𝐚𝐥𝐤 I'm a highly focused and motivated Mobile Team Lead developer at Itexus. Organized, methodical and a keen eye for detail results in solid coding and trustworthy mobile apps. Transforming client requirements into great apps based on a clear and quality code are core values in achieving long-lasting relationships. I have 7+ years of experience in mobile development using Android, Kotlin, Java, and iOS, Swift, Objective-C, Flutter. Technologies & Tools Kotlin | Java | Android | Swift | iOS | Dart | Flutter | KMM | KMP| Kotlin MutliPlatform | JavaScript | HTML | CSS | React Native | ReactNative | Native Mobile Development | Dagger 2 | Koin | GetIt | MobX | ReactiveX | Kotlin’s flow | Coroutines | Cicerone | Navigation Component | Realm | Room | Retrofit | OkHttp | Moshi | Scarlet | Apollo | Dio | Compose | ViewBinding | Splash Screen API (animated) | MPAndroidChart | RiverPod | Freezed | Groovy | Kotlin DSL Our Expertise at a Glance • Mobile App Development: Android, iOS, & Cross-Platform App Development using Java, Kotlin, Swift, Objective C, Flutter, and more. • Website and Full Stack Development: Crafting seamless back-end experiences with .Net, Python, Java, Javascript, React.js, Angular.js, Node.js, MERN, MongoDB, PHP, etc. • Logo & UI/UX Design: Bringing your ideas to life with Adobe XD, Photoshop, Sketch, Figma, etc. • End-to-End Solutions: From logo design, UI/UX development, workflow setup, testing to deployment in app stores, we've got it all covered. Why Choose Itexus? • Customized Approach: We tailor our services to fit your needs and budget. • Agile Workflow: Regular updates, milestones, or scrum sprints keep you in the loop. • Quality Assurance: Our meticulous testing process ensures that every project we undertake meets the highest standards of quality and functionality. • Competitive Price Assurance: We provide top-quality services at competitive prices to offer you the best value for your investment. • Guaranteed Success: We work tirelessly to exceed your expectations. Industries We Cover Healthcare, Transport, Retail, Asset Management, Wealth Management, Real Estate, Dating, Rental, Food Delivery, Fintech / Finance and Banking, Cryptocurrency, Entertainment, Hospitality, Non-Profit, Sports and Fitness, Travel and Tourism, Wellness, Medical Dashboard, Marketplace, Advertising, Automotive, Aircraft, Business Innovations, Human Resources, LegalTech, Lifestyle, Marketing, Education, E-learning, Insurance, IoT, E-commerce, Enterprise. Highlighted Skills Swift, iOS, Android, Kotlin, Java, IOS, Native programming Language | Project Planning | MVC Architecture and RESTful APIs | Front-end Technologies | React | HTML5 | CSS3 | JavaScript | Responsive and Mobile-first Design | Database Design and Implementation | MongoDB | Firebase | User Authentication | Integration of Third-party APIs | Deployment to Cloud Platforms | AWS | Test-driven Development | Agile Methodology | Scrum | Kanban | Security Technologies | QR Code Scanner | GPS and Mapping | Blockchain | NFT | Artificial Intelligence | E-commerce Solutions | Chatbots | Version Control Systems | Git | GitHub | Project Management and Collaboration Tools | ClickUp | Jira | Trello | Documentation and Code Commenting | SEO and Maintenance | MVP SAAS | Rebuild | Prototype | Start-Up | High-Friendly Custom Development | Transform | Solution | Ensure | Create | Enhance | Implement | Great Problem-solving | Excellent Communication | Assist | Collaborate | Mobile App Development | Web App Development | User Interface Design | Payment Integration | Stripe | Payment Gateway | ERP | CRM | User-friendly Interface | Mobile App Development | Mobile App Developer | Flutter App | Flutter Developer | Flutter Firebase | Flutter Dart | Flutter App Developer | App Developer | Mobile Developer | React Native | React Native Mobile App Development | Mobile App Builder | Flutter App Developer | Flutter Laravel | Mobile App Development | Mobile App Developer | Flutter App | Flutter Developer | Flutter Firebase Business with 1000+ Employees | Business with 10-99 Employees | Business with 100-999 Employees | Business with 1-9 Employees | Apple HealthKit | AI Marketplace | Waste Management & Remediation | AI App Development | Healthcare | Android App | Audio Conversion | ChatGPT API | Dating & Social Life | NFT Marketplace | Ecommerce Website Development | AI Speech-to-Text | Email Campaign Setup | API | Startup Company | Artificial Intelligence | Health Coaching | Health | Maintenance Management Talent Good Knowledge, Talented, Experienced, Skilled, Strong Experience, Proven Experience, Agency, Team, Company, Specialist, Proven Track Record, Strong Background, Write Clean Code, Deep Expertise, Bring to Life, Cross-platform, Attention to Detail, Long Term. ⚠️ 𝐏𝐫𝐞𝐬𝐬 𝐈𝐧𝐯𝐢𝐭𝐞 𝐁𝐮𝐭𝐭𝐨𝐧 𝐨𝐧 𝐦𝐲 𝐩𝐚𝐠𝐞 𝐚𝐧𝐝 𝐥𝐞𝐭'𝐬 𝐭𝐚𝐥𝐤

Backend Rest API
RESTful API
API
Blockchain
Android SDK
Flutter
Kotlin
C++
Swift
Firebase
API Integration
Android
Android App Development
iOS
$40 hourly
Rodrigo B.
- 5.0/5
- (2 jobs)
Hi there! I’m a Software Engineer with 10+ years of experience, specializing in cloud-based healthcare solutions (AWS, GCP) and HIPAA/GDPR compliant systems since 2018. My expertise is in designing secure, scalable, and AI-driven applications for healthcare professionals to improve patient outcomes. Recent Projects: ✅ Seizure Detection & Alerts – Developed a platform that notifies caregivers when epilepsy patients are about to have a seizure. ✅ Early Respiratory Disease Detection – Built a platform for COVID-19 early detection, in collaboration with Stanford University, the U.S. Department of Health, and the UK NHS. ✅ Remote Patient Monitoring (RPM) – Designed clinical trial and research-focused RPM solutions to enhance patient care and data collection. ✅ Led the design and implementation of a HIPAA-compliant data lake on AWS, optimizing secure data storage for healthcare applications and reducing operational costs and maintenance overhead ✅ Developed an AI-powered medical application for exchanging ePHI across facilities, integrating with LLM models (OpenAI) for conversational interactions ✅ Guided the implementation of audit controls and RBAC, ensuring compliance with HIPAA technical safeguards

Backend Rest API
Terraform
Cloud Computing
Node.js
Front-End Development
Angular
React Native
React
JavaScript
GitHub
RESTful API
Golang
Python
Java
API
Amazon Web Services
$35 hourly
Sergii K.
- 5.0/5
- (1 job)
More than 15 years of experience in web development. 13+ years SFCC (formerly Demandware) experience as a backend/fullstack developer. Strong problem solver, API and service integrations with minimal documentation. In-depth knowledge of SFRA structure and functions. Business Manager customization, Einstein, Page Designer, deep OCAPI hooks experience. Technology stack: Javascript, SOAP/REST, PHP, MySQL, HTML, CSS, and more. Proven ability to develop and optimize web systems for performance and scalability. Currently I have participated in more than 40 projects from medium to enterprise size. In late 2022, I was researching js frontend frameworks for Commerce API and decided to expand my knowledge in Next.js, React, and TypeScript as a whole.

Backend Rest API
NodeJS Framework
SOAP
Back-End Development
ECMAScript
RESTful API
Demandware
Node.js
HTML
PHP
JavaScript
Magento
$35 hourly
Artem V.
- 4.9/5
- (5 jobs)
I've been developing mobile applications using Flutter since 2020 (creating from scratch, redesigning, bug fixing, deploying). I also did web development in 2012-2018.

Backend Rest API
RESTful API
Figma
Clean Architecture
Git
Android
GraphQL
Firebase
Flutter
Dart
iOS
$125 hourly
Volodymyr M.
- 5.0/5
- (20 jobs)
Software engineer with 10+ years of experience in development and devOps. Recent projects: * Fintech project (golang) * Custom connectors for Zapier, Workato, Terraform, Crossplane, Pulumi * Datasets management platform for Computer Vision projects (python) * IoT platform (golang) Skills: golang, python, devops, custom integrations

Backend Rest API
Golang
Docker
RESTful API
DevOps
Terraform
Application Release Automation
Git
API
Python
Scripting
Zapier
API Integration
Automation
$60 hourly
Aliaksandr S.
- 5.0/5
- (5 jobs)
More than 10 years of production experience. I have good knowledge in different types of architectures: # Hexagonal/Onion/Clean Domain Centric Architectures # Classic 3 Layers DataBase Centric Architecture # Domain Driven Design # CQRS patterns, Event Sourcing, Event Streaming and Historical Modelling # Distributed Event-Driven systems, complex systems with SAGAs # Microservices, Docker, Containerised Apps & Kubernetes # Security with OAuth2 & OpenIdConnect, JWT, mTLS  I’m fond of designing encapsulated domain models (Domain Driven Design) and building Microservices using modern architectures with CQRS patterns. Skills: # C#, .NET, Web Api # Entity Framework, Dapper # T-SQL, MS SQL Server, MySQL # TDD, SpecFlow, unit & integration tests # SVN, Git, Scrum Biggest Projects ever worked on: # Senior Software Engineer at PaySafe - a market leader with over 25 years of experience in payments. My the most responsible task: I personally participated as a key developer in creating the backend architecture for a child PaySafe product: SafetyPay. It’s a high load system which processes millions of payment transactions a month.   # Elateral Marketing Service Cloud. I personally worked on the features for the following customers: Coca-Cola, Procter & Gamble, Motorola, Toyota. I used a NServiceBus SAGA to develop complex fulfilment process. There were more than 150 developers, QAs, BAs, Managers on the project. Methodologies I currently apply to my software development process: # Abstractions: this is important thing because it's the only way to build complex systems in easy way. Usually I use 5-8 abstractions maximum in a single piece of code/level because it's very difficult for a human brain to keep in mind more than 5-8 things at the same time. # Domain Driven Design # Profiling SQL queries # GoF patterns # SOLID principles # Estimating the complexity of algorithms O(1) O(N)... # Well designed REST apis # DRY # Microservices # Encapsulation

Backend Rest API
.NET Core
Domain-Driven Design
Test-Driven Development
Clean Architecture
RESTful API
Transact-SQL
C#
MySQL
Entity Framework
Microservice
$50 hourly
Nikolai D.
- 4.8/5
- (107 jobs)
Senior Full Stack Web Developer with 10 years experience Earned PHP Developer Certificate by Upwork (see "Certifications" section). Architecture planning and development for travel, oil, social networking and business sectors. Mobile API development, 3rd-party API integrations, REST/RESTful API implementations. Perform development, analysis, refactoring and management. 💪 My strongest skills are: 👉 App Structure: microservice architecture, RestAPI, SOAP 👉 BackEnd: PHP 5+ (MVC, OOP), Mysql, PostgreSQL 👉 FrameWorks: CodeIgniter, Symfony, Laravel 5+ 👉 FrontEnd: TypeScript, JS, Quasar, Vue.js 2 and 3, Vite, Pinia, Vuetify, Nuxt, Jquery, Bootstrap, Tailwind css, SCSS/SASS 👉 Working with Git, Composer, Webpack, npm, yarn, Vite 👉 Have experience in integrating the API's, such as Stripe, Paypal, QuickBooks 👉 Built RestAPI on CodeIgniter, Laravel, SPA on Vue 👉 Worked with Google Analytics and Google Tag Manager, Google Cloud Storage 👉 Manage servers: DigitalOcean, AWS, Linux 👉 Follow SOLID principles, love Agile methodology If you do something do it well or don't do it at all. This is one of my principles of my life, especially in my work. 💖 I like to solve complex tasks, automate processes, coding it's my passion. 🤝 Looking forward to building something amazing with you 🖖 Thank you for your attention.

Backend Rest API
PostgreSQL
PHP
MySQL
CodeIgniter
Amazon EC2
Laravel
Stripe
RESTful API
Vuex
Vue.js
Git
Nuxt.js
jQuery
Bootstrap
Tailwind CSS
$50 hourly
Oleksandr K.
- 5.0/5
- (8 jobs)
More than 10 years of successful development of a wide range of commercial web applications using .NET Core, ASP.NET, Web API, SOAP and REST Web Services, Xamarin and Cordova based mobile apps. Great architecture abilities for highly scalable solutions Microsoft Certified Software Developer: MCSD: Web Applications Experienced with Microsoft Azure cloud ecosystem, including Azure App Services, Azure Storage (Blob, Queue, Table), Kubernetes clusters and Service Fabric clusters. Have strong skills in Microsoft SQL Server and PostgreSQL. Had experience in Microsoft Bot Framework. Backend stack: .NET 6, .NET Core, Web API, .NET Core Identity, ASP.NET MVC, Entity Framework, Azure cloud platform, Google Cloud, AWS, Node.js Data storage: Microsoft SQL Server, PostgreSQL, MongoDB, Azure Cosmos DB, AWS Aurora, AWS Dynamo DB ORM: Entity Framework, Dapper, NHibernate No-SQL: MongoDB, Firebase DB, Redis, Elastic, Cosmos DB Frontend technologies stack: Vue.js, React, Angular, Javascript, Typescript, HTML5, CSS, Bootstrap, jQuery, LESS, SASS Test frameworks/tools: NUnit, xUnit, Selenium, Selenium Web Driver, Postman, jMeter Payment Systems integrations: PayPal, Stripe API, Flutterwave 3rd pary integrations: HelloSign, Google APIs, SigningHub, RestPack, Mailchimp, TINCheck, Experian, MasterCard MATCH, GIACT, Equifax, TransUnion Cloud solutions: Microsoft Azure, Google Cloud Services, Amazon Web Services Logging: Kibana, Elastic, Google StackDriver CI/CD: Azure DevOps,TeamCity, Octopus, Jenkins, Terraform Top projects: CRM System for Payment Gateway (NDA) Project goal: Migration from Salesforce to a self-developed CRM system with highly automated workflows Overview: CRM systems for US Payment Gateway business flows ie lead management, underwriting and processing of the third-party data ie Credit Score checks, Payment Gateways history checks, Fraud alerts Technologies: - .NET Core, .NET Core Web API - Entity Framework Core - PostgreSQL - Redis - React - Google Stack Driver - Kubernetes - Google Cloud Position / Responsibilities: Technical Lead of a team of 3 full-stack, 2 frontends and QAs Technical architecture design and implementation, requirements investigation, business process planning, task management License Plates Recognition (NDA) Project goal: Software for automatic license plate recognition. Creation of the infrastructure and apps for parking solutions in Europe. Overview: CRM systems for Parking Providers in Europe including booking, administration, and parking violations checks Technologies: - .NET Core, .NET Core Web API - Entity Framework Core - PostgreSQL - Elastic - Kibana - Kubernetes - AWS Position / Responsibilities: Technical architecture design and implementation, diagrams, documentation, requirements the investigation, business process planning, task management, optimization, scalability, code reviews 2018 – 2020 London-based Cloud Solution for Video/Image storage with image recognition and similarity detection (NDA) Project goal: Cloud software is primarily for creative people like designers, artists, and photographers to share their portfolios and do the edits and delivery online. Ability to find the best candidate for a job by uploading of a reference image. Ability to hire, track and pay for a job. Overview: Web solution for storing and editing the images and videos with the ability to share and portfolio management to find a job. Technologies: - .NET Core, .NET Core Web API - Entity Framework Core - MS SQL Server - Elastic - Vue.js - Azure Position / Responsibilities: Technical Lead / Architect Technical architecture design and implementation, diagrams, documentation Scalability enhancements Semantic core development for the image recognition and similarity detection software 2020 – 2021 Unity Mobile Game – Server Side Architecture and Development (NDA) Overview: Backend Development + CMS for a mobile game Technologies: - .NET Core, .NET Core Web API - Entity Framework Core - Amazon Aurora (PostgreSQL) - Elastic - Vue.js - Terraform - AWS Lambda - Web Sockets Position / Responsibilities: Technical Lead / Architect Backend performance tuning, Web Sockets implementation, AWS Lambda scalability and performance optimization, AWS cost optimization, CMS development (vue.js), API development, Business process overview, delivery planning 2021 – 2022 Warranties and loads for US automotive market Overview: US-based solution for auto warranties and loans with lead management and underwriting features Technologies: - CQRS pattern (MediatR) - .NET Core, Web API - Azure - Elastic - React - Azure DevOps - CosmosDB (Mongo syntax) - Web Sockets - Service Bus - Service Fabric, Azure App Services - Azure Functions (serverless) Position / Responsibilities: Technical Lead / Architect Third-party connection infrastructure development. Migration from Service Fabric to App Services. Performance optimization. Architecture review. High load stable infrastructure development.

Backend Rest API
API
.NET Core
.NET Stack
Microsoft Azure
Google Cloud Platform
RESTful API
Azure Cosmos DB
C#
ASP.NET
ASP.NET MVC
SQL
MongoDB
ASP.NET Core
PostgreSQL
Web Development
$44 hourly
Ihar D.
- 5.0/5
- (96 jobs)
Hi there! Looking for a developer who can bring your ideas to life on Wordpress? You found me! I have extensive experience with popular WordPress plugins such as WooCommerce, ACF, WPML, WPForms, MemberPress and many more. When creating and customizing themes, I can use any block editors such as Gutenberg, Elementor, Divi, as well as the no editor /classic editor option. I provide a full development cycle for popular CMS, as well as work with well-known frameworks for LAMP stack. I well versed in backend and front-end technologies and ready to create a website for you from beginning to finish or improve its functionality / performance / stability. In my practice I often work with various 3rd party API's, built the forms with different behaviors, create from scratch and adjust plugins and themes. I ready for short projects as well as long term partnership. I'm best in provide services like: - Developing sites and parts of them like themes, plugins, components, modules from scratch. - Upgrading CMS versions, plugins, components, modules. - Integrate different 3rd party API with your code. - From PSD to HTML layout preparing. - Making responsive site layout (mobile friendly, adaptive). - Setting Google analytics, tag manager, custom events and goals tracking. - SEO audit and subsequent correction of identified technical errors. - Page speed optimization. - Malware and viruses removing from sites and servers. - Web data scraping and manipulating. - Migration to another server/hosting/domain. - Restoring site from backup. - Cloning existing site. - Urgently fixing small bugs and issues.

Backend Rest API
Joomla
JSON
PSD to HTML
RESTful API
JavaScript
CSS 3
HTML5
AJAX
Gutenberg Editor
React
jQuery
MySQL
PHP
WordPress
SEO Audit
$60 hourly
Jan M.
- 4.9/5
- (32 jobs)
I am the go to guy resolving any tech problems in your company. Value is what I am focusing on. I am mostly experienced with Ruby on Rails and React so probably a full-stack engineer title sticks for me, but I am not only focusing on the programming work. My goal is to understand your business and its problems helping you operate more smoothly, worrying less about development. Delegate any challenge to me, I will find the solution to it allowing you to focus on your things. Background: As mentioned I am seasoned full-stack dev, mostly experienced with Ruby on Rails(also being it's open-source contributor) and React. But during over 6 years been working on vast majority of projects in many different programming languages and on different positions. I am not scared of building web scrapers, reporting tools or managing servers(DevOps). Being an all-rounder helps me understand the businesses on multiple levels and have a broad perspective which results in the happiness of my freelancing clients. Project Highlights: 🔹 COVID-19 Vaccination Passport Platform: I architected a system from scratch for a major German city, efficiently managing over 500,000 records, ensuring security, and maintaining high scalability during peak demands. 🔹 Telehealth Platform for Physiotherapists: I spearheaded a redesign of search functionalities, achieving a tenfold improvement in performance and markedly enhancing the user experience. 🔹 Marketing Automation Platform: My implementation of AI-driven messaging and data enrichment strategies has saved hundreds of hours and notably increased conversion rates. Client-Centric Approach: 🌟 Problem Solving: I dive deep into each project's unique challenges, ensuring solutions are tailor-made to address specific needs. 🌟 Value Delivery: Each solution is designed to maximize ROI, whether through enhanced efficiency, increased security, or scalable growth. 🌟 Technology Expertise: As an official Ruby on Rails contributor, I bring authoritative knowledge and innovative practices to every project. Technical Skills: 🛠 Languages: Ruby, JavaScript, SQL, Elixir, Python, HTML/CSS 🛠 Frameworks/Tools: Ruby on Rails, React, Docker, GitHub Actions, RSpec 🛠 Databases: PostgreSQL, MariaDB, Redis, AirTable

Backend Rest API
RubyMotion
Airtable
RubyMine
IT Consultation
Ruby on Rails Stack
Database Integration
API Integration
Ruby on Rails
JSON API
RESTful API
API Development
PostgreSQL
Ruby
JavaScript
$500 hourly
Ivan N.
- 5.0/5
- (32 jobs)
🥇Expert-vetted (top 1%) Upwork freelancer. 💡Top AI voice in LI. 👔 10+ years of experience on executive tech positions. ⭐️⭐️⭐️⭐️⭐️ "Ivan seamlessly navigated the complexities of the non-deterministic nature of OpenAI/LLMs. Highly recommend! Ivan - Exceptional work on our POC. Thank you." ⭐️⭐️⭐️⭐️⭐️ "Amazing to work with. Went above and beyond expectations." ⭐️⭐️⭐️⭐️⭐️ "Ivan understands AI and LLMs really well, he’s a great communicator and transparent about his methods and efforts." ----------------------- Hello! I'm all about technology and the magic it brings to our lives. . There's something truly special about building things from scratch and watching them take off. With a solid foundation in tech, I have a particular interest in the final product — its user experience, design, and the customer's journey. Collaborating with product and business teams is something I thoroughly enjoy, as it brings together different perspectives for a common goal. My area of expertise lies in Artificial Intelligence, Machine Learning, and Natural Language Processing. Here are some of the services I commonly offer: - Strategic AI audits and guidance - Elevating existing products with AI enhancements - Designing and developing new AI-centric solutions - PoC/MVP for AI projects I've had the privilege of working with over 50 companies, including notable names like UBS, Yahoo, STC, and Hitachi. This experience has allowed me to contribute significantly to the growth and transformation of various products. Interested in exploring how AI can revolutionize your product? I'd love to chat about your vision and how we can bring it to life. Feel free to reach out, and let's start a conversation about your next big step in innovation. ----------------------- Some of my AI and ML skills include: ✅ Data Science and Machine Learning expertise including Deep Learning, Natural Language Processing, and Computer Vision using TensorFlow, PyTorch, Keras, scikit-learn, Numba, etc. ✅ API Development and Integration, including external API integration like OpenAI API. ✅ Expertise in Reinforcement Learning and its applications in complex environments using libraries like OpenAI Gym, Stable Baselines, and RLlib. ✅ Advanced skills in data preprocessing, feature engineering, and dimensionality reduction techniques for machine learning models. ✅ Proficiency in time-series analysis and forecasting using ARIMA, LSTM, and Prophet for predicting future trends. ✅ Development of chatbots and virtual assistants using platforms like Dialogflow, Rasa, and Microsoft Bot Framework. ✅ Experience with Generative Adversarial Networks (GANs) for creative applications such as art generation, style transfer, and data augmentation. ✅ Implementation of recommendation systems using collaborative filtering, content-based, and hybrid approaches. ✅ Proficient in big data analytics using Apache Spark, Hadoop, and related ecosystems for handling large-scale data processing. ✅ Knowledge of edge computing and deploying AI models on edge devices using TensorFlow Lite, PyTorch Mobile, and ONNX. ✅ Expertise in computer vision tasks like object detection, image segmentation, and facial recognition using OpenCV and Dlib. ✅ Strong background in mathematics and statistics, essential for algorithm development and model optimization. ✅ Experience with cloud platforms like AWS, Google Cloud, and Azure for deploying and scaling machine learning models. ✅ Capable of conducting AI-driven research and development, staying at the forefront of emerging technologies and methodologies. ✅ Ability to communicate complex AI/ML concepts to non-technical stakeholders and collaborate effectively with interdisciplinary teams. P.S. Curious about the future of AI in your industry? Drop me a message, and I'll share my insights and predictions!

Backend Rest API
RESTful Architecture
RESTful API
NGINX
Web Application
Database Architecture
API Integration
Elasticsearch
Hibernate
Spring Framework
Java
Docker
Microservice
Apache Kafka
Kubernetes
Architectural Design
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