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Hire the best Java Developers in Warsaw, PL

Check out Java Developers in Warsaw, PL with the skills you need for your next job.
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Rating is 4.9 out of 5.
4.9/5
based on 188 client reviews
  • $60 hourly
    • 5.0/5
    • (6 jobs)
    🎯 What Value Can I Bring to Your Business? 🚀 I help businesses achieve digital transformation goals by delivering scalable, high-impact solutions. Whether you need to automate workflows, optimize performance, or integrate cutting-edge AI technologies, I bring the expertise to turn your ideas into reality. ✅ Save Time & Reduce Costs by automating repetitive tasks and streamlining operations. ✅ Improve Performance & Scalability with robust backend architectures that grow with your business. ✅ Enhance User Experience by integrating seamless APIs and cloud-based solutions. ✅ Stay Ahead of the Competition with custom AI tools that offer actionable insights and intelligent automations. ✅ End-to-End Platform Development - From concept to launch, I can build entire platforms tailored to your business needs, covering everything from backend architecture to frontend design. 💼 How I Ensure Success: Discovery & Consultation 📋 - Understanding your unique needs and business objectives. Solution Design & Documentation 📐 - Creating a roadmap with clear deliverables and timelines. Development & Integration 🛠️ - Building secure, scalable, and efficient systems tailored to your requirements. Testing & Deployment ✅ - Ensuring your solution is production-ready with rigorous testing. Ongoing Support & Optimization 🔄 - Providing continuous improvements and feature upgrades to keep your system future-ready. 🤝 Let's Connect and Build Something Great Together! 🔧 Technical Skills & Technologies 🖥️ Programming Languages: Java (Spring Boot, Hibernate) Python (FastAPI, Django) ⚙️ DevOps & Cloud: Docker 🐳 & Kubernetes ☸️ for containerization and orchestration CI/CD pipelines (GitHub Actions, Jenkins) AWS ☁️ (EKS, S3, Lambda) Azure & Google Cloud Platform (GCP) 📊 Databases: PostgreSQL 🐘, MongoDB 🍃, MySQL Redis for caching ⚡ 🤖 AI & Machine Learning Tools: OpenAI GPT integrations Custom LLMs (Large Language Models) deployments NLP (Natural Language Processing) and NER (Named Entity Recognition) solutions 🔗 Integration Expertise: I specialize in integrating with platforms like: Twitch, WhatsApp, TikTok, Instagram, Facebook Monday.com, GoHighLevel, Make.com, Zapier Payment gateways, CRMs, ERPs, and more!
    Featured Skill Java
    Solution Architecture
    Software
    OCR Algorithm
    ChatGPT
    Django
    Spring Boot
    Make.com
    Zapier
    Automation
    DevOps Engineering
    Python
    Artificial Intelligence
  • $25 hourly
    • 5.0/5
    • (35 jobs)
    Minecraft Server Developer Extraordinaire Hello, I'm Pawel, a seasoned Minecraft server developer with over 7 years of experience in crafting and optimizing immersive gaming environments. Expertise: 🛠️ Minecraft Server Development: Crafting robust servers and plugins, staying updated with the latest trends. 💻 Java Programming: Creating efficient, secure, and high-performance code. 🧰 Development Tools: Skilled in IntelliJ IDEA and managing databases with T-SQL and PL/SQL. ⚙️ Systems Management: Expert in managing and optimizing Minecraft server systems. 🌐 Server Technologies: Proficient in Paper (Spigot) and BungeeCord configuration. 🚀 Redis: Extensive knowledge in using Redis for caching, pub/sub messaging, and synchronizing multiple servers for real-time data consistency. 🔌 API Integration: Enhancing functionality and connectivity with API integrations. 🖥️ Swing Applications: Developing modern and functional Swing applications. 🤖 Additional Skills: Web scraping, automation, algorithm optimization, and bot development. Collaboration: Passionate about creating seamless Minecraft experiences. Let's collaborate to bring your Minecraft vision to life. Contact: Ready to transform your Minecraft project? Contact me today and let's craft extraordinary adventures together.
    Featured Skill Java
    Proxmox VE
    System Administration
    Apache Maven
    Gradle
    Swing
    DNS
    Network Engineering
    Redis
    SQL
    Plugin Development
    JetBrains IntelliJ IDEA
    Minecraft
    phpMyAdmin
    Linux
  • $40 hourly
    • 5.0/5
    • (2 jobs)
    A seasoned CTO with over 10 years of experience in the tech industry. I can help you develop an application or website starting from doing the estimation up to the delivery and maintenance. My services: React, Node.js, React Native, Ruby on Rails, Ruby, Python, Django, Flask, Java, AWS, No-Code Development, DevOps, JavaScript, Flutter, Serverless Stack, GCP, AWS, API Gateway. Checkout some interesting projects I worked on in the work history and portfolio sections below ⤵️
    Featured Skill Java
    Google Cloud Platform
    AWS Development
    Full-Stack Development
    Web Development
    No-Code Development
    Serverless Stack
    DevOps
    Flutter
    React Native
    Node.js
    React
    Python
    JavaScript
    Ruby
  • $40 hourly
    • 5.0/5
    • (48 jobs)
    💻 My greatest strengths are my extensive experience and deep expertise in React development and Project Management. I’ve successfully completed numerous projects using React for both web and mobile applications and am committed to continuously enhancing my skills. Here are some key metrics showcasing my professionalism: ⭐ 11,000+ hours worked on Upwork ✅ 70+ successfully executed projects 🔧 Excellent troubleshooting skills 🏆 Exceptional Top Rated Plus engineer 👍 70+ satisfied customers Focusing on React, I deliver high-performance front-end applications and full-stack solutions, leveraging my skills in API integration, automation, and mobile development. Whether creating dynamic web applications or building mobile apps, I provide efficient and scalable solutions. I am proficient in a wide array of technologies, including: 🚀 Key Skills: ⚛️ React, React Native, Redux, JavaScript, Node.js, API Integration 🌐 Full-Stack Development, Web Development, API Integration 🛠️ MongoDB, Express.js, AngularJS, Web3.js, PHP, WordPress 📱 Mobile Development (iOS, Android, Flutter), Firebase, Automation 💻 TypeScript, CSS, HTML, PHP, AI App Development 🤖 Google Chrome Extensions, Hybrid App Development ☁️ Microsoft SQL Server, Microsoft Graph API, Python 📈 SEO, GitHub, ChatGPT API Integration Keywords: Mobile App Development, Android, Android App Development, Dart, Expo.io, Firebase, Firetime Realtime Database, Flutter, FlutterFlow, Hybrid App Development, In-app Purchases, iOS, iOS Development, Java, Kotlin, Native App Development, Push Notifications, React Native, Swift, User Authentication, UX Design. Web Development: React, React.js, Redux, TypeScript, UI/UX Design, AngularJS, API, CSS, Debugging, Express.js, Firebase, GitHub, Google Cloud Platforms, HTML, JavaScript, PHP, PostgreSQL, Web Development, WordPress. Full-Stack Development: API Development, Backend, CSS, Dart, Express.js, Full-stack Development, MongoDB, Node.js, PHP, Push Notifications, Redux, Vuex. AI Development: AI App Development, AI Model Integration, AI Text-to-Speech, ChatGPT API Integration, Machine Learning. I thrive in agile environments, delivering high-quality results and collaborating effectively with cross-functional teams. My deep knowledge of React and full-stack technologies allows me to create solutions tailored to your business needs. If you're looking for a reliable, detail-oriented developer, I'm your go-to expert. 🌟 Check out my portfolio, work history, and client reviews to see my reliability! When you're ready, just send me an invite, and I’ll be happy to help you bring your dream app to life—one that not only generates revenue but is also something you’ll be proud of! 🚀💼
    Featured Skill Java
    Flutter
    API
    Front-End Development
    Back-End Development
    Mobile App Development
    React Native
    Artificial Intelligence
    API Integration
    JavaScript
    React
    MongoDB
    Web Development
    Full-Stack Development
    Node.js
  • $85 hourly
    • 5.0/5
    • (8 jobs)
    Experienced Java developer with solid skills of system design and analytical mindset. I also have engineer's degree in computer science.
    Featured Skill Java
    Vert.x
    Cucumber
    Micronaut
    JUnit
    Apache Groovy
    Microservice
    Hibernate
    SQL
    Spring Framework
    Git
  • $45 hourly
    • 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.
    Featured Skill Java
    Amazon Web Services
    MySQL
    MongoDB
    Spring Boot
    Kubernetes
    RabbitMQ
    RESTful API
    Elasticsearch
    Docker
    Hibernate
    Spring Framework
    SQL
    Apache Kafka
  • $40 hourly
    • 5.0/5
    • (4 jobs)
    I’m a Java Software Engineer with various experiences across many different technologies. Eager to tackle new technical challenges and functional discussions.
    Featured Skill Java
    SonarQube
    Axon
    Database Design
    Spring Boot
    API
    Apache Tomcat
    Database
  • $55 hourly
    • 5.0/5
    • (3 jobs)
    I'm a Senior Software Engineer with over 9 years of experience, I have gained extensive expertise in designing and implementing high-quality software solutions that meet the client's business requirements. Throughout my career I was working on multiple projects, here I'm sharing three of the most challenging ones: At UBS (a Swiss bank with a $60bln capitalization), I was a Senior Java Developer, and I was responsible for developing a regulatory reporting engine to handle dozens of millions of transactions the bank processes daily. This project was part of implementing their new business requirements around designing a project on an entirely new event-driven technological stack. There were several main challenges that I faced when designing and implementing the system: 1. System should handle millions of transactions per day that have to be reported in a timely manner. 2. System should be tolerant to hardware failures, including the loss of the entire data center. 3. Around 40 developers should be able to work on the project productively with minimal conflicts. 4. Correctness of reporting is essential – every introduced bug can have disastrous consequences – the system should have checks in place that prevent buggy code from being deployed to production. 5. Transaction reporting domain is very complicated, and business requirements are frequently changing. System design should be flexible enough to adjust to the required changes. 6. There are multiple stakeholders involved; each has different requirements for the system. At Denario, a fintech startup, I worked as a Senior Java Developer, assuming full responsibility for designing, developing, deploying, and maintaining the application and DevOps tasks. The main challenges in the projects were: 1. Developing a high-performance system 2. Integrating with multiple Open Banking providers 3. Ensuring the platform was scalable, fault-tolerant, and highly available 4. Ensuring the platform was secure and user data was protected 5. Collaborating with the product team to design features that met users' needs 6. Maintaining the platform and fixing issues that arose in production 7. Assuming full responsibility for the end-to-end software development process At the Ministry of National Defense of Poland, I was a Team Leader and Technical Leader responsible for providing e-learning solutions for hundreds of thousands of users. My role involved leading a team of developers, analysts, and testers to develop and maintain a learning management system. I have experience working with a variety of technologies, including: Java, Spring Framework, Spring Boot, Hibernate, JUnit, Spock, Apache Flink, Kafka, PostgreSQL DB, Oracle SQL DB, Elasticsearch, Microsoft Azure, Kubernetes, AWS I am passionate about software development and strive to stay up-to-date with the latest trends and technologies. I am dedicated to delivering high-quality solutions and exceeding client expectations.
    Featured Skill Java
    API
    Spock
    Spring Framework
    JUnit
    Unit Testing
    Linux
    Apache Kafka
    SQL
    Bash Programming
    Spring Boot
    Linux System Administration
    Bash
  • $35 hourly
    • 5.0/5
    • (1 job)
    I'm Senior React Native & React developer. Love to create incredible applications & solve complex tasks. 𝗪𝗵𝗮𝘁 𝘆𝗼𝘂 𝗰𝗮𝗻 𝗲𝘅𝗽𝗲𝗰𝘁 𝗳𝗿𝗼𝗺 𝘄𝗼𝗿𝗸𝗶𝗻𝗴 𝘄𝗶𝘁𝗵 𝗺𝗲? ✅ Trust ✅ On-time delivery ✅ Great communication level ✅ Daily Updates During my 7+ years of experience in React Native & React I'v implemented a lot of features, complex tasks including: ✔ Developing Apps from scratch to release ✔ CI/CD for Mobile and Web applications ✔ Maps Integration ✔ Push Notifications ✔ Localization ✔ Upgrading to newer React Native & ReactJS versions ✔ Routing ✔ Social Media Login (Google | Apple | Twitter | Linkedin) ✔ Location Service
    Featured Skill Java
    Web Development
    Next.js
    Google Maps API
    CI/CD
    iOS
    Android
    Firebase
    iOS Development
    Android App Development
    Hybrid App Development
    JavaScript
    TypeScript
    React
    React Native
  • $75 hourly
    • 5.0/5
    • (8 jobs)
    I'm a java developer with experience in building scalable applications. My main area of expertise is java but also I have some experience with c# technology and web technology. Like angular and react.
    Featured Skill Java
  • $65 hourly
    • 5.0/5
    • (4 jobs)
    During my time in university, I mainly focused on process automation, optimization, modelling and artificial intelligence. After my graduation, I got myself involved in several projects concerning the above, but I was also forced to develop mobile apps and web apps which based on our solutions. Currently I've found myself between projects so I decided to make some money on the side.
    Featured Skill Java
    Database
    Technical Project Management
    Database Management System
    MATLAB
    Tech & IT
    Microcontroller Programming
    HTML
    JavaScript
    Python
    CSS
    PostgreSQL
    C++
  • $45 hourly
    • 5.0/5
    • (1 job)
    I have established myself as an experienced and responsible specialist. I love challenges, and I consider myself a stress-resistant person. As for me, my core soft skill is problem-solving. Also, I am very attentive to details and patient.
    Featured Skill Java
    React
    Web Development
    Linux
    Oracle
    JavaScript
    Artificial Intelligence
    Software Development
    SQL
    Python
    PHP
    API
    Docker
    Spring Boot
  • $35 hourly
    • 5.0/5
    • (4 jobs)
    Hello! I'm an AI Expert with a flair for transforming complex challenges into actionable solutions. With over 2 years in the industry, I've honed my skills to the point where I can confidently say, AI isn't just my profession—it's my passion. Some highlights from my career: Chatbots & Virtual Assistants: I played a pivotal role in crafting a lead-closing chatbot for a million-dollar enterprise. Predictive Analytics: For e-commerce company, I implemented a recommendation system that increased their cross-sell rate by 18%, substantially elevating their average transaction value. The AI landscape is vast and ever-evolving, and I am always at the forefront, ready to harness its potential for my clients. I believe that every challenge is unique, and so should be its AI solution. Let's collaborate and create something exceptional for your business!
    Featured Skill Java
    Artificial Intelligence
  • $35 hourly
    • 5.0/5
    • (3 jobs)
    Hello! Thank you for taking the time to review my profile. I am a highly versatile full-stack software engineer with over 7 years of experience. I specialize in transforming ideas into scalable products that serve thousands to millions of users. I am committed to delivering high-quality solutions and ensuring client satisfaction. 🥇 Skills Breakdown Languages: ECMAScript, TypeScript, Python 3, HTML, CSS, Sass, SCSS, GraphQL, Objective-C, Swift, C#, and more. Frameworks: Express.js, Bootstrap, Electron, Spring Boot, and more. Libraries/APIs: Redux, React Redux, jQuery, Vuex, and others. Tools: Docker Compose, GitHub, Slack, and more. Storage Solutions: Redis, OpenXML, and others. Development Paradigms: Functional Programming, Continuous Integration/Deployment, and more. Platforms: DigitalOcean, Windows, iOS, Android, and more. Additional Skills: Cloudflare, IT Security, Chrome Extensions, and more. 🥇 Experience Senior Software Engineer: Over 5 years Front-end Development: 7 years Full-Stack Development: 7 years I look forward to collaborating with you. Please feel free to 🎁INVITE🎁 me!
    Featured Skill Java
    React Native
    Flutter
    Vue.js
    web3.js
    Django
    Laravel
    Ruby on Rails
    Next.js
    Node.js
    React
    Ruby
    Python
    TypeScript
  • $70 hourly
    • 5.0/5
    • (3 jobs)
    I’m a translator, developer, and content creator with experience in IT, marketing, and digital media. With a background in IT Management, I have a strong foundation in coding, business, and finance, allowing me to approach projects from both a technical and strategic perspective. What I Offer: • Fluent English-Turkish translations (learning Polish, Korean, and Japanese) • Web development & e-commerce solutions (Shopify, HTML, Java, C#) • Video editing & marketing content creation • Project management & digital strategy I ensure clear communication and a solution-oriented approach in every project. Let’s collaborate!
    Featured Skill Java
    Voice-Over
    Content Writing
    Translation
    C++
    Python
    Marketing Analytics
    Accounting
    C#
    Project Management
    Management Skills
  • $90 hourly
    • 5.0/5
    • (11 jobs)
    Experienced Java EE, JavaScript, SQL developer. Over 6 years of experience in developing Web and Enterprise Applications. Backend: Java, Spring, Hibernate, IBatis/MyBatis, JAX-WS, JAX-B, Jersey, XSLT, Ruby on Rails, Docker, Telegram API Frontend: JavaScript, ReactJS, AngularJS, jQuery, HTML, CSS, Bootstrap, GWT, JSF, JSP. Version control: Mercurial, Git, SVN
    Featured Skill Java
    iBATIS
    React
    CSS
    Spring Framework
    JavaScript
    AngularJS
    Hibernate
    HTML
  • $35 hourly
    • 5.0/5
    • (19 jobs)
    Greetings, I proudly serve as the CTO at Intelliceed, a distinguished company with a relentless focus on Web App development. Our expertise spans diverse sectors, including: ✅ FINTECH ✅ HEALTHCARE ✅ SOCIAL NETWORKS AND MARKETPLACES ✅ E-LEARNING/LMS ✅ DOCUMENT MANAGEMENT SOFTWARE Our mission is nothing short of transformational: we are dedicated to making people's lives more convenient and efficient. Since our inception in 2017, Intelliceed has been at the forefront of improving the quality of life, having successfully delivered over 20 bespoke projects. Our team comprises exceptional talent, including React.js virtuosos, Java experts, DevOps maestros, Project Managers, and QA engineers. Our Impressive Technology Stack: 🔹 Back-End ✔ Java, Spring, Next.js ✔ Kafka, Jenkins, Docker, Kubernetes ✔ Hibernate, Redis, RabbitMQ ✔ AWS (SQS, DynamoDB, SNS), Azure, GCP ✔ MySQL, PostgreSQL, Elastic Search 🔹 Front-End ✔ JavaScript, React, React Native, Next.js, Angular ✔ HTML, CSS 📌 Our primary mission is to empower STARTUPS, BUSINESS OWNERS & FOUNDERS, and DIGITAL AGENCIES by supplementing their teams with seasoned engineers and developers. We are poised and ready to assist you with a wide range of services, including: 🔸 Web Application Development 🔸 Consulting and Business Analysis 🔸 Hybrid Applications Development 🔸 DevOps implementation with AWS, Azure, GCP cloud providers 🔸 Database Application Development 🔸 Manual and Automatic QA Our Engagement Models 🔥 Dedicated Team – Your extended, fully managed development team 🔥 Project Outsourcing – End-to-end project development 🔥 Outstaffing – Directly hiring skilled engineers 🔥 Team Recruitment – Assembling a team tailored to your project How It Works: 🔹 Introduction – We begin by understanding your request. 🔹 Talent Matching – Our team selects the right talent or team for your needs. 🔹 In-Depth Research – We analyze your request and define tailored collaboration terms. 🔹 Proposal & Negotiation – Intelliceed presents a customized proposal and refines it with you. 🔹 Contract Signing – We formalize the agreement. 🔹 Collaboration Begins – We launch our partnership and start working together. You can initiate a free consultation regarding your project to witness how we can synergize effectively. Send me an invite, and together, we'll embark on the journey of building remarkable projects that leave an indelible impact! Let's turn your vision into a reality. 🚀 🔥🔥🔥What Our Clients Say About Their Experience Working With Us ⭐⭐⭐⭐⭐ The guys are creative, proactive, and not afraid of difficulties. ⭐⭐⭐⭐⭐ We’re very impressed with the work that the team did. ⭐⭐⭐⭐⭐ We couldn't be happier and never experienced any performance or management issues with the IntelliCeed team. Everything we planned was correctly estimated and met all the milestones. ⭐⭐⭐⭐⭐ I broadly gave them instructions on what I wanted and they were able to produce it for me. ⭐⭐⭐⭐⭐ They're focused on delivering value. 𝐒𝐤𝐢𝐥𝐥𝐬 𝐢𝐧 𝐉𝐚𝐯𝐚 & 𝐄𝐧𝐭𝐞𝐫𝐩𝐫𝐢𝐬𝐞 𝐃𝐞𝐯𝐞𝐥𝐨𝐩𝐦𝐞𝐧𝐭: 🔸 Java, Java EE (Servlets, JSP, JSTL) | Java Core, OOP, Collections & Stream API 🔸 Spring Framework (Spring Boot, MVC, Security, Data JPA) | Hibernate, JPA 🔸 RESTful API Design | OpenAPI | Swagger | Cucumber 🔸 Databases: PostgreSQL, MySQL, Oracle, MSSQL, MongoDB, DynamoDB 🔸 Frontend: JSF, PrimeFaces, jQuery, GWT, AngularJS, HTML/CSS/JS 🔸 Message Queues: RabbitMQ, ActiveMQ | Cronjobs & Event Handling 🔸 Servers: Tomcat, JBoss, WebSphere, WebLogic, Jetty, Apache, Nginx 🔸 DevOps & Tools: Docker, Jenkins, GitHub Actions, Git (GitHub, GitLab, Bitbucket), SVN, Maven, Ant, Liquibase 𝐒𝐨𝐟𝐭𝐰𝐚𝐫𝐞 𝐄𝐧𝐠𝐢𝐧𝐞𝐞𝐫𝐢𝐧𝐠 & 𝐀𝐫𝐜𝐡𝐢𝐭𝐞𝐜𝐭𝐮𝐫𝐞: 🔹 Strong command of Object-Oriented Programming & Design Patterns 🔹 J2EE Design Patterns, MVC Architecture, Facade/Service Layers 🔹 Data & Product Modeling | Import/Export Pipelines | Integration Layer 🔹 Test-Driven Development (TDD): JUnit, Mockito, AssertJ, Hamcrest 🔹 Cloud Platforms & Services: AWS (S3, SNS, SQS, DynamoDB) 🔹 API & Payment Gateway Integrations (Stripe, PayPal, Braintree, etc.) 🔹 Agile Methodologies: Scrum, Kanban | CI/CD with Jenkins, GitLab 🔹 Extensive experience in FinTech, Healthcare, Real Estate, and HR Systems 𝐇𝐢𝐠𝐡𝐥𝐢𝐠𝐡𝐭𝐞𝐝 𝐒𝐤𝐢𝐥𝐥𝐬: Java EE Development, Enterprise Architecture (J2EE, MVC), Spring Framework (Boot, Security, Data JPA), RESTful API Development, Front-End Integration (JSF, PrimeFaces, jQuery, AngularJS), Microservices & Messaging (RabbitMQ, ActiveMQ), Containerization (Docker), Database Design (PostgreSQL, Oracle, MongoDB), Payment Systems Integration, Cloud Technologies (AWS: S3, SQS, SNS, DynamoDB), Testing & QA Automation (JUnit, Mockito, Cucumber), DevOps Practices (CI/CD with Jenkins, GitHub Actions, Maven), Agile Project Management, Version Control (Git, GitHub, GitLab), Cross-domain Experience (FinTech, Healthcare, Real Estate, HR Tech) Last updated: April 2025
    Featured Skill Java
    Full-Stack Development
    Front-End Development
    Back-End Development
    Spring Boot
    Scala
    React
    Core Java
    Spring Security
    SQL
    Spring Framework
    AngularJS
    Google Web Toolkit
    Hibernate
    MongoDB
  • $65 hourly
    • 4.9/5
    • (49 jobs)
    Highly skilled software developer with over 12 years of experience delivering exceptional solutions to clients. I specialize in full-stack development, including expertise in back-end, front-end, and DevOps, making me well-equipped to tackle complex projects. I have a proven track record in developing robust, scalable, and user-friendly applications across various industries, including finance, healthcare, and e-commerce. With excellent communication skills and a strong commitment to collaboration, I ensure smooth project delivery and successful outcomes. I am ready to bring my expertise to your next project on Upwork Back-end technologies and languages: - Java, Spring Boot, JPA/Hibernate + Spring Data - Scala, Play Framework, Akka - Node.Js, Express, Nest.Js, TypeScript - Maven/Gradle/SBT/NPM - Mysql, PostgreSql, MongoDB, Redis - GRPC, Protobuf DevOps and Microservices: - Linux/Unix - Docker - Nginx - Kubernetes - Prometheus - ELK stack Front-end technologies: - HTML/CSS/JavaScript - Angular - React
    Featured Skill Java
    NestJS
    Kubernetes
    Spring Boot
    Microservice
    API
    MongoDB
    Node.js
    Angular
    TypeScript
    Scala
    PostgreSQL
    React
    Amazon Web Services
    JavaScript
  • $62 hourly
    • 4.9/5
    • (17 jobs)
    I’m a software engineer with a master’s in economics and deep business expertise, specializing in finance automation and all kinds of software integrations. Before I started automating entire departments (sales, finance, recruitment) in my own businesses and cutting costs by up to 70%, I led the development of software for businesses of all sizes - from small North American family businesses to global giants like Bosch & Siemens. ——— Longer version ——— I started working on finance process automation as a software engineer back in 2011. Since then, I’ve been constantly optimizing business workflows, streamlining operations, and integrating financial systems. When I co-founded a couple of service businesses, I finally had the freedom to design financial processes from the ground up, applying lean automation strategies instead of building full-scale software solutions. By automating my CFO responsibilities, I reduced financial admin work to just four days a month - and with that extra time, I began helping other businesses achieve the same results. ✅ QuickBooks/XERO Automation – Reduce manual work with API-based automation. ✅ HubSpot/Zoho → QuickBooks/XERO - integration and automation ✅ OCR – Extract text from scanned and handwritten financial documents. ✅ Custom API Integrations – Sync CRM data with QuickBooks, marketing, and ops tools. ✅ Workflow Automation – Build and optimize automations with n8n. ✅ Reporting – Automate reports and create custom dashboards. ✅ Human in the Loop – Add approvals for sensitive operations. AI for Operations: ✅ Virtual Helpdesk - provide basic support and customer onboarding via phone. ✅ Anomaly & Error Detection – Identify unusual or suspicious payments in QuickBooks. ✅ Inbox Agents - no more manual data entry for Finance and Sales. ✅ Transaction Classification – Automatically categorize expenses and income. Case Studies 📌 Automated QuickBooks for a SaaS Company Set up QuickBooks integrations and automated financial workflows, reducing manual data entry by 80%. Implemented API-based syncing with their CRM and payment systems. 📌 Financial Process Optimization for an Outstaffing Business Built a system that streamlined invoice processing and automated reconciliation, cutting month-end closing time in half. Used n8n for workflow automation and AI-based OCR for document processing. 📌 Custom Reporting & Dashboards Developed automated dashboards for financial tracking, ensuring real-time insights into cash flow and expenses. 📩 Let’s discuss how I can help you automate your financial operations!
    Featured Skill Java
    n8n
    CRM Automation
    Automation
    Task Automation
    API Integration
    API
    Python
    JavaScript
    Intuit QuickBooks
    QuickBooks Online API
    QuickBooks Online
    Xero
    Finance
    Financial Report
  • $60 hourly
    • 4.9/5
    • (17 jobs)
    With a rich background in software development, I specialize in Java and related technologies. My experience spans teaching, back-end development, and architecture, involving diverse projects from large-scale platforms to tailored client applications. Currently, I focus on designing and deploying cloud-based back-end solutions with a specialization in serverless architecture, security, integrations, and databases. I've collaborated with global corporations, provided consultancy services, and freelanced for SMEs and startups. My project portfolio ranges from high-traffic e-commerce applications to data-centric and cutting-edge solutions like low-code platforms and AI-integrated tools. Leveraging my extensive experience, I not only offer technical expertise but also provide valuable business insights to clients, advising on the strategic aspects of their applications. Moreover, I hold AWS certifications and boast a strong educational background with degrees in Computer Science and Organization Management.
    Featured Skill Java
    Amazon S3
    Continuous Integration
    API Development
    Amazon EC2
    AWS Lambda
    AngularJS
    Hibernate
    Spring Framework
    SQL
  • $60 hourly
    • 5.0/5
    • (11 jobs)
    10+ years of software engineering experience. Former UpWork employee (was laid off with 21% of the workforce). My goal is to help you achieve more spending less time and money. Working on Ptah.sh - Docker Swarm-based Heroku and Vercel alternative. I have rich experience working with different technologies: from PHP & Python, through JavaScript and Go, to mobile development with React Native and Flutter. Started multiple projects on my own: - e-sportstats.com - where I was a CTO and led a small team of 5 engineers - ptah.sh - Docker Swarm-based Heroku alternative where I am the sole founder and engineer Among that, I lead various conferences and made a couple courses for internal use for the companies I've been working with.
    Featured Skill Java
    Laravel
    Django
    MySQL
    PostgreSQL
    Spring Boot
    JavaScript
    PHP
    Python
    Demandware
    React
    Node.js
  • $35 hourly
    • 5.0/5
    • (180 jobs)
    ✅ 250+ successfully completed contracts, 7 years of programming experience 💼 Founder of fast-growing outsource agency. I can offer you services of: - Mobile App Development: Creating responsive and intuitive apps for iOS and Android using React Native and Swift. - Web App Development: Crafting interactive and scalable web applications with HTML, CSS, JavaScript, Angular, and React. - Game App Development: Designing engaging and immersive games using Unity and Unreal Engine. - 2D&3D Design - WatchOS / tvOS Development - Project Management I’m ready to drive your project to success. Let's discuss your development needs today!
    Featured Skill Java
    UX & UI
    ARKit
    VR Application
    AR & VR
    AR & VR Development
    SwiftUI
    Mobile App Development
    Smartphone
    Virtual Reality
    Native App Development
    Swift
    Kotlin
    iOS
    Android
  • $35 hourly
    • 5.0/5
    • (15 jobs)
    With over three years of experience leading Android development teams, I specialize in creating innovative mobile solutions that elevate user experiences. My expertise spans a wide range of skills, including Android development, technical documentation, product management, app deployment, and software architecture. I excel in team leadership, fostering collaboration and driving continuous improvement, while skillfully managing conflict resolution and ensuring smooth operations. Proficient in Java and Kotlin programming, version control systems, API integration, and database management, I bring technical depth to every project. From managing issue tracking systems to optimizing apps for social media platforms, I thrive on delivering high-quality results and pushing the boundaries of mobile technology to achieve exceptional outcomes. I am confident that my skills and experience align perfectly with your needs, and I am excited about the opportunity to contribute to your project. Thank you for considering my application. I look forward to the possibility of working together.
    Featured Skill Java
    RESTful Architecture
    JavaFX
    JSON
    Git
    Kotlin
    Android App Development
    In-App Advertising
    Smartphone
    Android SDK
    API Integration
    SQLite Programming
    Chat & Messaging Software
    Android
  • $20 hourly
    • 5.0/5
    • (5 jobs)
    With over six years of experience in software development, I excel in creating scalable, secure applications using Java, Spring Boot, and Spring MVC. My technical expertise includes Hibernate, Thymeleaf, PostgreSQL, and RESTful Architecture, ensuring robust and efficient solutions. I have successfully delivered full-stack applications and managed cloud infrastructures with AWS and Terraform, optimizing performance and cost-effectiveness. My experience in microservices and database management with PostgreSQL guarantees structured and secure data access. I am a problem solver with a focus on clean, maintainable code, and I prioritize client communication to align with business objectives. My education and continuous learning in software development further enhance my ability to deliver innovative solutions. I am eager to bring my skills to your project and help achieve your goals with cutting-edge software solutions.
    Featured Skill Java
    API Integration
    Apache Kafka
    Microservice
    Spring MVC
    REST API
    PostgreSQL
    API
    RESTful Architecture
    SQL
    Spring Boot
    Thymeleaf
    Hibernate
  • $43 hourly
    • 0.0/5
    • (0 jobs)
    ♟𝐑𝐞𝐯𝐨𝐥𝐮𝐭𝐢𝐨𝐧𝐢𝐳𝐢𝐧𝐠 𝐭𝐡𝐞 𝐝𝐞𝐥𝐢𝐯𝐞𝐫𝐲 𝐨𝐟 𝐝𝐢𝐠𝐢𝐭𝐚𝐥 𝐩𝐫𝐨𝐝𝐮𝐜𝐭𝐬📲 🚀 As an IT professional with more than 8 years of experience I am developing enterprise solutions for top-tier companies, including several on the Forbes USA list. Throughout my career, I’ve successfully built multiple MVPs from scratch - each contributing to meaningful business growth and high customer satisfaction. Driven by a passion for quality and deep technical expertise, I consistently aim to deliver outstanding, innovative solutions that address complex challenges 💎 𝐊𝐞𝐲 𝐅𝐚𝐜𝐭𝐬 𝐀𝐧𝐝 𝐆𝐮𝐚𝐫𝐚𝐧𝐭𝐞𝐞𝐬 8+ years of proven expertise 90+ worldwide 🌎 projects 8 out of 10 clients come by recommendations 👨‍💻 𝐌𝐲 𝐓𝐞𝐜𝐡 𝐀𝐫𝐬𝐞𝐧𝐚𝐥: Programming Languages: Java, Node.js, JavaScript, TypeScript, Python, HTML5, CSS3, SCSS Front-end: React.js, Next.js, Redux, Tailwind, Vue.js, Nuxt.js, Angular, ES12+, Bootstrap Back-end: Node.js, Nest.js, Express.js, Laravel, Spring Boot, Spring Security, Spring Cloud, Spring MVC, Spring Data, Django Databases: MySQL, PostgreSQL, MongoDB (Mongoose), Kafka, RabbitMQ, Redis, JPA/Hibernate, Liquibase, Flyway, R2DBC CI/CD & DevOps: Docker, Kubernetes, Helm, GitLab CI/CD, Jenkins, Terraform, Maven, Gradle, Nginx + PM2 Cloud Services: AWS (EC2, EKS, S3, Lambda, Cognito, Route 53, CloudFront, Certificate Manager, DynamoDB, SQS, CloudWatch), GCP (Cloud Storage, Cloud Functions), Azure Cloud Monitoring & Analytics: Datadog, Kibana, Grafana, ElasticSearch, New Relic Other Tools: WordPress (Custom Theme & Plugins), Strapi, LaraNova, Scikit-learn, Pandas, Keras, TensorFlow, Auth0, Firebase, Telegram API, Binance API, MacOS, Linux Ubuntu LTS 18.04, Windows 10, IntelliJ IDEA, Postman, JIRA, Confluence, SonarQube, Splunk, Slack, Snyk Microservices & Distributed Systems: Microservices architecture, Monolithic (multi-layered/DDD), Monorepo (Nx), Resilience4J, JUnit, Mockito, Apache Commons, Akka, Netty Web3/Crypto: Implemented a trading bot with Binance API using a trailing stop strategy; basic proficiency in Solidity smart contracts; developed a KYC system 👉 Click the 🟢 INVITE 🟢 button to bring your ideas to life! Our fusion of technical mastery and industry know-how ensures every solution is crafted to exceed expectations fostering real, measurable business outcomes 📅🛫🎯🌟 🔎 Keywords to Help You Find Me: Full-stack developer, Web Development, SaaS development, WordPress, Website development, HTML, JS developer, JavaScript, Website Audit, Landing Page development, AI development, Discord, Gaming Full-stack developer, React developer, Node.js, Web app, SaaS, Startup development, Python, React.js, Next.js, Redux, Typescript, Tailwind, Node.js, Nest.js, Express.js, Vue.js, CMS Strapi, Pandas, MySQL, MongoDB, PostgreSQL, Java, Spring Boot, Microservices, Docker, Kubernetes, Terraform, AWS, GCP, Azure Cloud, Binance API, Web3
    Featured Skill Java
    SaaS Development
    Amazon Web Services
    API
    Minimum Viable Product
    PostgreSQL
    Database Development
    JavaScript
    Microservice
    Back-End Development
    Web Development
    Spring Boot
  • $45 hourly
    • 0.0/5
    • (1 job)
    As a Quality Assurance Specialist I am responsible for conducting manual and automated testing to ensure that the company's final products and processes meet established quality standards. Therefore, if you are looking for professional validation, verification and communication through documented testing - I am here to help! Looking forward to our cooperation! Maciej Nikonowicz, Polcode Dev Team
    Featured Skill Java
    Selenium
    Testing
    Exploratory Testing
    Cypress
    JavaScript
    SQL
    Python
    Apache JMeter
    Test Case Design
    Functional Testing
    API Testing
    Postman
    Integration Testing
    Regression Testing
  • $30 hourly
    • 5.0/5
    • (8 jobs)
    Senior Full Stack Engineer with more than 5 years of experience. CS Bachelor. Certified AWS Architect. Full cycle of Web application development: design, implementation, testing, deployment, support. I will help you develop low-cost, reliable, fault-tolerant and highly available cloud-based web application. Key technologies: * AWS: Lambda, EC2, ECS, DynamoDB, etc. * Java: Spring Framework, Hibernate, etc. * JavaScript: Webpack, React, Redux * DevOps: Docker, Kubernetes, Jenkins
    Featured Skill Java
    Microservice
    Spring Framework
    React
    DevOps
    JavaScript
    PostgreSQL
    Hibernate
    MongoDB
    Node.js
    Jenkins
    CI/CD
    Kubernetes
    Amazon Web Services
    Docker
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