Name: Java developers
Brand: Upwork
Rating: 4.7 (2024 reviews)

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Clients rate Java developers

4.7/5

based on 2,024 client reviews

$35 hourly
- 5.0/5
- (7 jobs)
As an experienced Full Stack Developer with over 6 years in the field, I bring a wealth of expertise in Node.js, .NET Core, and ReactJS. With a solid foundation in both front-end and back-end technologies, including Full-Stack Development, I excel in creating scalable web applications and APIs. My proficiency spans a range of technologies, from C#, JavaScript, TypeScript, Python, and C++, to robust Web Development frameworks and libraries such as React (with Hooks and Redux), Angular Ts, and Vue Js. Skilled in Agile methodologies, I focus on developing scalable microservices and innovative front-end features, ensuring a seamless user experience that leverages the best of Web Design and Software Design principles. My commitment to quality is evident in my attention to detail in Software Architecture & Design, as well as in meticulous Software Testing. In the realm of database engineering, I am adept in Database Architecture and Database Design, with hands-on experience in SQL-Server, NoSQL, PostgreSQL, Firebase, and MongoDB. My expertise extends to crafting responsive and intuitive Mobile App Development and Desktop Applications, utilizing technologies like .NET Framework, React Native, Ionic, and Cordova for both Android and Hybrid App Development. Additionally, I am proficient in AI Development, including Speech-to-Text Conversion, Text-to-Speech Synthesis, and fine-tuning AI Models for enhanced performance and accuracy. My toolkit is complemented by knowledge in CSS, HTML, WordPress, Figma, and RESTful API integration, enabling me to deliver comprehensive solutions across platforms. Whether you're in the startup phase or scaling up as a large enterprise, my focus is on delivering top-tier software development services that align with your business needs, ensuring quality, efficiency, and client satisfaction. My expertise in Microsoft Windows environments, cloud platforms such as AWS and GCP, and modern development tools, positions me to handle a variety of challenges, driving your success through technological innovation.

Java
Software Architecture & Design
Python
HTML
TypeScript
C++
Software Design
Web Design
API
JavaScript
Node.js
Web Development
.NET Framework
React
C#
$100 hourly
- 5.0/5
- (28 jobs)
Hi! I'm just your average senior software whiz with a ton of hands-on know-how. Throughout my career journey, I've been the captain of some pretty massive squads and cooked up seriously scalable stuff using all the cool tech toys like: + Python (with Flask and Django) + JS (with React and Angular) + C++ + Java (with struts & spring). + MySQL + AWS/GCP + Stripe/Paypal/Auth.net By the way, my work clock follows Eastern Standard Time (EST), and I'm chilling right here in the good ole US of A ;)

Java
C
MySQL Programming
jQuery
CSS
C++
HTML5
Python
JavaScript
PHP
$60 hourly
- 5.0/5
- (11 jobs)
I’m a multilingual PERN Full-Stack Developer with 3 years of professional work experience working at some of the largest gaming companies in the world, as well as a few start-ups. My biggest strengths are JavaScript, SQL, Html, CSS Java, NodeJS, Express.JS, ReactJS, PostgreSQL, Spring Framework, Thymeleaf, Bootstrap, Python, Heroku, Cloudflare, Selenium, Firebase, and REST API. I have experience working in Full-Stack development, as well as web automation.

Java
PostgreSQL
ExpressJS
Tailwind CSS
Thymeleaf
React
Node.js
Selenium
Spring Framework
Bootstrap
JavaScript
CSS
HTML
SQL
Python
$50 hourly
- 4.8/5
- (34 jobs)
I'm a software engineer with extensive experience in building Mobile Apps and Web Apps. My experiences include working with modern technologies like Flutter/Dart, React Native, Native iOS and Android, Java, Angular, and several other Web & Mobile technologies. With more than 8 years of experience in development and customization of Mobile and Web applications, I have become expert at solving complex problems and creating state of the art solutions, I like working on projects with a team that cares about creating beautiful and usable interfaces. It's important to me to build long term relationships with clients, so I'm primarily looking for long term projects. I'm flexible with my working hours and am happy to work closely with any existing freelancers you work with. My aim is to provide quality and professional solution that is easy to implement, user-friendly and highly optimised. I'm very much oriented towards customer satisfaction and quality of work. If this is what you want, then get in touch with me, I believe you'll adore working with me, I look forward to hearing from you!

Java
Web Design
Trello
MEAN Stack Administration
Basecamp
Web Development
AngularJS
Zeplin
HTML5
$60 hourly
- 5.0/5
- (53 jobs)
Working with cloud based serverless systems, writing firmware, designing pcbs, developing web apps, coding in python and others (c,c++,flutter/dart,php,html5,java,javascript,sql,nosql,etc.), providing exceptional service, and maintaining attention to detail. Desktop: Linux focused but can provide code for other platforms. (and flutter apps) Backend: AWS focused, lambda, api gateway, dynamodb, cognito Hardware: circuit design, pcb design, PCBA Firmware: work with various MCU's, familiar with multiple frameworks,sdk's,idk's Mobile: Android native and flutter development MCU's: esp32, nRF52, nRF53, nRF91, smt32, rp2040, + others (TI, Microchip) IoT hardware and firmware design: 4g, BLE, WiFi, Lora, GPS, Matter, Mesh

Java
Embedded Linux
Electrical Engineering
Android
Amazon Web Services
C
C++
Python
PHP
$56 hourly
- 5.0/5
- (11 jobs)
Android Experience: o Kotlin and Java o Jetpack Compose, XML, and view binding o Android Studio IDE and Google Play Publishing Console o Firebase libraries: Auth, Realtime Database, FireStore, GeoFire, and Analytics o Google Maps and Location Client Services o Support Library o Consuming Restful APIs using Volley and Retrofit o Permission Requests o Material Design o Proguard o Google Games Services: Sign-In, Achievements, and Leaderboards o Unit Testing o AdMob iOS Experience: o Swift o Map View o Game Center Sign-In, Achievements, and Leaderboards o Eureka o Sticker Packs Tech Experience: o Parsing JSON/XML o MVVM and MVC o Github VCS o CircleCI o Agile Methodologies o TFS/Trello Kanban Boards o Freshdesk o LibGDX Framework o Tiled Level Editor o Davinci Resolve, Adobe Premiere Pro, Adobe Photoshop, and Gimp

Java
English
Email Etiquette
Technical Support
Mobile UI Design
Mobile App Testing
Swift
iOS Development
Kotlin
Android App Development
$195 hourly
- 5.0/5
- (24 jobs)
Hi! I'm James, a Harvard Computer Science graduate, an ex-Googler, and CTO-level fullstack software engineer. I have 21 years of work experience, and can meet in-person if you’re in or near silicon valley. I believe that brilliance is good; reliability is better; and most important are integrity and compassion.. I help awesome people doing amazing things in the world; and I will deliver you delightful tech and tech leadership, on time, on budget, with full transparency and candor. I provide the following services: - Fractional CTO: I will work with you to clarify your visionary goals into an actionable technical roadmap; help you secure funding if necessary; and then run the technical operation start to finish. - Web and native app development: From napkin-sketch ideation to 7+ figure production, I will deliver intuitive, elegant digital experiences to your customers, from top-rated games and 3D virtual worlds to FDA compliant medical software, on the web and on devices. - Solving “unsolvable” tech problems. Examples of real projects I was engaged for: building a low power “hurricane proof” weather camera (Weather Channel); assisting with the development of the Semantic Reactor (a Google/Alphabet internal project); building a physical neural network entirely out of glass. - Technical project management: I will ensure your project runs on time and on budget, with incremental milestones and mitigated risks, using the best of Agile and PM tooling. I can manage teams large and small. - Productionalizing Research. Give me the research paper or the patent, I’ll make it real and scalable. - Consulting, with lawyers and attorneys, as a software engineering resource, for instance with respect to contracts and other legal matters (like Privacy Policies or GDPR/CCPA concerns). - Modernization of old technology: I will migrate and modernize your legacy application using the industry’s latest best practices. I have experience with performance tuning, scalability, devops, security hardening, penetration testing, and much more. - Teaching and coaching: I teach middle and high schoolers competitive coding. I enjoy tapping into every student’s life story and motivations. I also advise entrepreneurs and can act as a sounding board for personal and professional goals. - Solutions Architect: I provide comparative analysis of modern cloud technologies and explanations of how to use them for different scenarios. For example, I delivered a research paper to a private equity firm comparing Kafka, Kinesis, and other message queue technologies. The following are some of the technologies I have experience with: • Languages: Javascript/Typescript (ES6, ES7), C and C++, Java, Kotlin, Scala, Python, C#, Go / Golang, Rust • Analytics and Automation: make.com, Zapier, Twillio, Vercel, Airtable, Tableaux, Salesforce • Web: HTML5/CSS /SCSS/SASS/CSS-in-JS, React, Angular, WASM, 3js / three.js, Svelte, Astro, Vue.js, Qwik, Next.js, internationalization/i18n, localization l10n, accessibility/a11y • AI: PyTorch, TensorFlow, ChatGPT, GPT3 and GPT4, GAN (generative adversarial networks), Transformers, LSTM, RNN, belief networks / HMM • Mobile: ios (Swift and Objective-C), Android (Kotlin, Java) and DEX / Dalvik debugging, Google Play, App Store, React Native, expo • Geospatial: S3, H2, KD-tree, quadtree, ArcGIS, choropleths, NLP (including slack and discord chat bots) • MVP and Project Management: Figma, Trello, Jira, Agile, Scrum, Kanban • Testing and QA: JUnit, Jest, Mocha, Chai, Selenium, Puppeteer, Playwright, Cypress • Backend: NodeJS, Express, Django, flask, Tomcat, Spring, RabbitMQ • Infrastructure and DevOps: Docker, Kubernetes/k8s. GitHub Actions, CircleCI, Jenkins, Vercel, Netlify, Gatsby, Drone, Vagrant, Chef, Ansible, Terraform • Auth and InfoSec: auth0, oauth2, pentest, ISO 27001, GDPR, CCPA • Cloud tech: AWS, Azure, GCP, EC2, S3, Lambda, Kafka, Kinesis, AppSync, Spark, Storm, DataFlow, Hadoop • Databases: MySQL, Postgres, Firebase, Mongo, DynamoDB, Redis, NoSQL • Games / 3D: Unity, Unreal, OpenGL, webgl, photogrammetry, Meshlab, Blender, OpenCV • Embedded Tech: IoT, Raspberry Pi, Arduino, • Code Management: Github, Gitlab, Gerrit, Git, Svn • DevOps and Command Line: Bash, ZSH, Linux, PowerShell, Make, ImageMagick, FFMpeg, cron, GNU core tools

Java
PyTorch
NodeJS Framework
TensorFlow
Artificial Intelligence
React Native
Unity
Apache Kafka
Raspberry Pi
Scala
Python
JavaScript
Android
Bash Programming
Enterprise Architecture
$50 hourly
- 5.0/5
- (3 jobs)
I possess an extensive proficiency in Angular 2+ framework, which I have adeptly utilized in collaboration with two distinct companies to architect scalable front-end solutions. Through these partnerships, I have contributed significantly to the advancement of front-end technology. Moreover, my expertise extends to orchestrating, transitioning, operating, and upkeeping WordPress sites. Recognizing the paramount significance of SEO for commercial platforms, I am well-versed in leveraging my mastery of Google AdWords to bolster the online visibility of clients within search results. Furthermore, I have adeptly navigated the intricacies of AWS to facilitate the development of resilient and cost-effective back-end systems. My proficiency lies in collaborating seamlessly with product owners to guarantee the precise realization of product objectives, firmly grounded in a well-defined 'definition of done'. In the realm of back-end development, I have consistently employed Java Spring Boot, serving as the cornerstone for all my undertakings. My professional trajectory showcases a comprehensive experience in crafting RESTful services that seamlessly interact with cloud-based databases, complemented by seamless integration with Angular-based front ends. In addition, I bring a wealth of Kubernetes expertise to the table. I have adeptly orchestrated containerized applications, effectively managing their deployment, scaling, and automation. This experience enhances my ability to architect end-to-end solutions that encapsulate both front-end excellence and back-end robustness. Together, my seasoned proficiencies across Angular, WordPress, SEO strategies, AWS, and Kubernetes ensure a holistic approach to crafting technology solutions that seamlessly blend innovation, scalability, and strategic visibility.

Java
WordPress Theme
AWS CloudFormation
WordPress Development
Swift
Angular
Spring Boot
Bootstrap
HTML5
JavaScript
$50 hourly
- 4.9/5
- (14 jobs)
I am a Delaware-based Full Stack expert. I have done a lot of successful projects as a Web and Mobile app developer for the last 7 years. I have worked with many startups, mid-scale, and enterprise clients and provided them with the best return on their investment. Along with that, I also have extensive experience with ✳️ Flutter, React Native, Kotlin, Swift, and Java Languages. ✳️ React.js, Angular.js, Vue.js, Python, Node.js, Express.js, Next.js, Nest.js, PHP, Laravel, Magento ✳️ AWS Services like Cognito, IAM, Lambda, API Gateway, Dynamo DB, etc. ✳️ Serverless Architecture Design & Product Development ✳️ Firebase Integration for Real-time Database, Notifications and data storage My goal is to make demanded and highly-rated projects. I have enough experience and can work hard to achieve it. Also, I provide service after projects completion. Strengths and Skills:- ✔️ iOS: Swift & Objective C ✔️ Android: Java & Kotlin ✔️ Web: React.js, Angular.js, Vue.js, Python, Node.js, Express.js, Next.js, PHP, Laravel, Magento ✔️ Game Development: Unity ✔️ AWS, Firebase, PlayFab, Photon. ✔️ Monetization SDKs. ✔️ Google Maps Integration in iOS and Android! ✔️ Deliver on Time, the best quality work! ✔️Expert in Git & BitBucket ✔️Project Management tools: Jira, Asana, Basecamp, Trello ✔️No Code Platform: Caspio, Retool, Bubble.io, FlutterFlow, Builder.io ✔️AR/VR Development ✔️Game Development All ears to hear your ideas and I can help you build the Solution/Product you are looking for. Best!!

Java
Mobile Game Development
Game Development
Web Development
UX & UI Design
SwiftUI
AWS Development
Cloud Services
Xamarin
React Native
Flutter
Kotlin
Augmented Reality
Android
Swift
$75 hourly
- 4.6/5
- (20 jobs)
A Senior Software Engineer with a strong background in developing innovative APIs and software applications. My expertise lies in JavaScript, TypeScript, Node.js(NestJS/Express.js/Strapi), React, Next.js, Vercel, React Native, Tailwind CSS, HTML5/CSS3, Material UI, AngularJS/Angular, Ruby on Rails, Python/Django, FastAPI, Hubspot, and Restful APIs, among others. I have a proven track record of successfully integrating digital applications with physical devices, focusing on scalability, security, and interoperability. I've worked closely with cross-functional teams to align API development with user requirements and mission objectives. My innovative approach to connectivity challenges has resulted in improved device communication and user experience. I'm skilled in implementing rigorous testing and optimization to ensure API stability and performance. My experience also includes designing and developing desktop applications, incorporating machine learning techniques, and ensuring data security and privacy. I'm proficient in utilizing AWS, Electron, and GitHub Actions for cloud-based services, native desktop environments, and CI/CD. The projects I contributed have received positive feedback for their innovative approach to accessibility and data security.

Java
FastAPI
Django
Ruby on Rails
RESTful API
Amazon Web Services
ExpressJS
NestJS
Web Development
Web Application
Next.js
Node.js
TypeScript
Python
React
$40 hourly
- 5.0/5
- (14 jobs)
Hi, I'm Oliver, and I have spent the past 5 years building mobile and web applications for startups and small businesses. I can take your wireframes and transform them into a full-fledged app you can put before real users in just weeks. With my fully custom, user-friendly, designs and my quick, scalable backend architectures, I will make your visions a reality. I am a student of computer science at Colorado College and I spend my free time writing code. I specialize in native iOS development and full-stack web development with a broad range of skills across many different languages and frameworks. I love working with new technologies and tackling tricky problems! I am especially interested in developing open-source projects that can make a difference in the world. Let's talk about your project! Here are the skill sets I have: IOS DEVELOPMENT:- Swift SwiftUI Spotify SDK Google Admob Revenue Cat Firebase Mapkit Healthkit AVFoundation WEB DEVELOPMENT:- HTML Javascript CSS React Next js Node js jQuery tailwindcss Spotify API Prism Flask Stripe Sendgrid Next Auth Cloud: - Lambda Functions Elastic Beanstalk Eventbridge Firebase CouchDb MonogoDb CosmosDb Api: - Express Flask SQL Next js Web3: - Solidity Wagmi IPFS Sign-In With Ethereum

Java
Next.js
Full-Stack Development
Spotify
CSS
Web Application
HTML
Back-End Development
Apple Xcode
iOS Development
Swift
JavaScript
Python
React
Firebase
$80 hourly
- 5.0/5
- (22 jobs)
Let's build a next-generation product. I love building on the edge of technology. I've built my fair share of websites with the latest javascript frameworks. I am very familiar with Angular. I am comfortable doing backend server work as well. I held a previous position supporting logistics and distribution center servers at Walmart Labs and developing new features that were used on a day-to-day basis in operations. I have done a few large projects through UpWork focusing on Ionic Applications using both Cordova and Capacitor versions. My largest project being with Morgan and Morgan using Ionic Angular Capacitor. Message me about a phone call if you are interested.

Java
Spring Data
Angular 2
Spring Boot
TypeScript
Microsoft SQL Server
MongoDB
JavaScript
$60 hourly
- 4.7/5
- (12 jobs)
Experienced Full Stack developer helping small businesses and startups develop custom apps. I have developed from the ground up and published several apps to the app store which have a lot of 5 stars. Pre-launch support: • Backend API development and integration • Frontend development • Testing and Quality Assurance • App Store Submission and Approval Post-launch support: • Maintenance/Bug Fixing • Further Extensions Areas of Expertise: • Swift, Objective-C, React Native, React.js, Typescript, Flutter, Dart, C#, Xamarin, Python, Django, Node.js/Express, Angular, .NET Cloud services: • Firebase, Crashlytics, AWS Misc: • Jira, Git, Slack, TestFlight, AppStore Contact me if you're working on any interesting projects! I consult people for FREE and would be happy to help you if you have any questions about your project or idea! Cheers!

Java
Shopify
C#
Dart
Flutter
Swift
Kotlin
TypeScript
React Native
Firebase
Objective-C
Mobile App Development
React
$50 hourly
- 5.0/5
- (55 jobs)
I specialize in creating and optimizing custom trading strategies, indicators, and tools for Metatrader 4/5 using MQL and for TradingView using Pine Script. With a deep understanding of trading APIs, I integrate seamless solutions to enhance your trading experience. As a full-stack web developer, I build modern, responsive websites using Django, Node.js, Next.js, and React.js, complemented by sleek designs with Tailwind CSS. I deploy applications on any server platform, including AWS and Google Cloud, and can integrate various payment methods. My expertise in working with APIs allows me to turn your ideas into reality efficiently and effectively. Let's collaborate to bring your vision to life.

Java
React
Node.js
MetaTrader 5
Forex Trading
MetaTrader 4
Swift
NoSQL Database
MQL 4
MQL 5
AWS Application
SQL
C++
Python
JavaScript
$38 hourly
- 5.0/5
- (15 jobs)
Hello! As a freelance full stack developer with expertise in various languages including C, C++, Delphi, C#, Java, Python, HTML, CSS, Javascript and SQL, I can assist you in building a wide range of applications and systems based on your needs. If you require a simple CRUD application, I can create a user-friendly interface and implement the necessary functionality to manage your data efficiently. Whether it's a basic application or a more complex one, I have the skills to deliver high-quality results. Building websites is another area of my expertise. I can design and develop websites of any kind, whether it's a personal blog, an e-commerce platform, or a corporate website. I am proficient in HTML, CSS, and JavaScript, allowing me to create responsive and visually appealing websites. If you need to build an API (Application Programming Interface) for your application, I can design and develop RESTful APIs that allow seamless communication between different systems or services. I can ensure that your API is secure, scalable, and well-documented. Complex web automation is also within my skill set. I am experienced in using libraries such as Requests and Beautiful Soup for tasks like data extraction and manipulation. Additionally, if you prefer to use Selenium for web automation, I can work with that as well. Scraping data from websites is another area where I can assist. I can develop scripts or tools to extract specific data points or gather information from multiple sources, providing you with the required data in a structured format. Importing and exporting data is crucial for many projects. Whether you need to migrate data between systems or integrate data from different sources, I can design and implement efficient solutions to ensure smooth data transfer and synchronization. Throughout the development process, I prioritize clean code, maintainability, and performance. I follow industry best practices and utilize version control systems to ensure the reliability and quality of the software I deliver. As a freelance developer, I am self-motivated and committed to delivering high-quality results. I am eager to collaborate with you and build exceptional software solutions that meet your specific needs. Let's work together to bring your vision to life!

Java
JSON
Importing & Exporting Data
Web Scraping
Web Development
Automation
Scripting
API Development
Problem Solving
Flask
SQL
Python
Linux
JavaScript
C#
$60 hourly
- 5.0/5
- (17 jobs)
Greetings, I'm Aaron, a software engineer with 11 years experience. I am an expert at Java and Spring Boot, while also being well versed in many other languages, JavaScript, NodeJS, PHP, C++. I know web very well, so HTML, CSS, React, and various other frontend tech. The databases I use include MySql, Postgresql, Mariadb, Mongo, Redis, Kafka and others. I work on the following sorts of projects: - Creating REST APIs and developing backends - Database design and implementation, optimizations - Building web apps, both internal and external - Integrations between systems, writing custom integration code - Custom automations, usually in code. - IT work, setting up servers and cloud infrastructure, scalable systems - Anything at all related to Java, Spring Boot, and this ecosystem I can do the entire lifecycle for your software, you just tell me the requirements, I'll get it done.

Java
JavaFX
Stripe
SOAP
J2EE
RESTful Architecture
RESTful API
Amazon Web Services
React
JSON
XML
JavaScript
Apache Maven
Spring MVC
Spring Security
Spring Boot
$94 hourly
- 4.9/5
- (16 jobs)
I develop high quality iOS and Android mobile apps using Swift, Kotlin, Java, SwiftUI, Jetpack Compose, Firebase, and APIs as needed depending on project. Through my hard work and dedication to meet all project requirements, I've earned Upwork's Top Rated Plus rating! I am self-motivated, self-directed, dependable, reliable, and trustworthy. I've been an independent consultant for most of my career. I know how to conceive a project, get the work done independently, and successfully deliver the project. I excel at testing so when the project is done, it is done! No one likes to put together a large programming team where there are tons of duplicated effort and miscommunication. I can be your single-source developer for both Android and iOS phones and tablets! Most apps also need a back-end. No need for a separate web app programmer that can cause timeline problems and miscommunication! I can write the back-end utilizing Firebase then integrate it into all versions of your mobile app. Using a single source, you control the timeline, you avoid integration issues, and everything flows smoothly. You probably cut your delivery time in half! Every week, I develop mobile apps, cloud functions, and cloud tasks, mainly for Internet of Things using Bluetooth and Firebase. Every week, I am using: Kotlin Java Javascript, typescript, node.js (back-end) Swift Jetpack Compose SwiftUI Bluetooth (Android) Core Bluetooth (iOS) Firebase Auth (user authentication, login) Firebase Firestore (database) Google Cloud Functions Google Cloud Tasks (scheduled based on a trigger) Firebase Crashlytics Firebase and Apple push notifications Google sign-in Apple sign-in As an expert Mobile App Developer, other skills I can deliver: Flows, co-routines, async tasks, flow state. WiFi configuration: static IP, dns, enterprise, add and update. JSON serialization/parcelization. NFC tag reading. Develop Maven library. Network Service Discovery (NSD). Direct ipp open protocol for printers. REST - okhttp and retrofit expert for network calls, including calls to Amazon AWS. User accounts with encryption tokens. Encrypted keystore. Push notifications (Firebase, Apple, in-app). Silent package Installer and updater. Kiosks management. Google maps with location updates, custom map markers, annotated map markers. Custom User Interface features with custom graphics, backgrounds, themes, and styling. User authentication. Credit card validation. Stripe credit and debit card processing. Google Pay processing. Glide or Picasso image handling/transformation. Image upload as file or bitmap. Dark mode activation. Launch and welcome screens with terms of service. Multi-threaded environment solutions and multi-tasking co-routines. Dynamic updates of screens from incoming push notifications. Phone dial, messaging, camera photo-taking, gallery browsing. Backwards compatibility to older versions of Android. Forwards compatibility to latest versions of Android. Room database. App publishing on Google Play Store and Apple App Store. App testing on Firebase. Firebase/Maps API keys. Troubleshooting and expert debugging of crashes/bugs/memory leaks in legacy apps. Development environment: Gradle multi-flavor (multi-version) builds Github and bitbucket version control Slack or Jira team communication Figma wireframes Swagger REST API calls Github or Jira project management and collaboration Roll-outs to 50 million user install base A recent review on Upwork: "Stephanie did a superb job to make our Bluetooth hardware on-boarding via Android very reliable. She was able to find the corner cases and then find solutions for those corner cases! This was a difficult challenge as Bluetooth permissions, capabilities, and processes vary greatly between Android OS versions and devices. The on-boarding process is simple, elegant, and extremely user friendly. It has been an honor and pleasure working along side Stephanie." Other: Protocol Stacks, embedded systems, multi-tier networking systems Fortune 500 Java and C/C++ Trainer, Expert Witness Computer Science degree, Certified Project Management Professional Native English Speaker Available to work any timezone Background: I've used many protocol stacks: Point-to-point, TCP/IP, sockets, WiFi CDMA network, Bluetooth, other wireless networks. I've developed application systems with 4 tiers of communication layers: Device to Handheld, Handheld to PC, PC to mini-computer, mini-computer to mainframe. Embedded Systems: Transponder readings sent to handheld which then transferred data to desktop computer which interfaced to IBM mainframe. Cable system "set-top" box. Assembly code for micro-chips. Veriphone credit card readers with communication to mainframes/cloud. Java Trainer for Sun Microsystems (before they were bought out by Oracle) for 2 years. C/C++ Trainer for Intel University (part of Intel) for 2 years. Expert Witness in trial against a top insurance provider regarding their Java based application.

Java
Software Debugging
Database
API Integration
Swift
Push Notifications
Firebase
Android
iOS Development
Firebase Cloud Firestore
RESTful API
Android App Development
Kotlin
Bluetooth
JetPack
$80 hourly
- 5.0/5
- (13 jobs)
As a passionate software developer based in California, I've always been drawn to the dynamic world of web and software development. My journey has led me to specialize in both coding and managing websites with WordPress, significantly expanding my portfolio. I thrive in environments that challenge my adaptability and problem-solving skills, whether working solo or collaborating with teams. I take pride in my ability to dive into complex projects, guiding them from conception to launch. My technical background is diverse, spanning the creation of large-scale applications designed for client interaction to implementing cutting-edge, open-source technologies that push the boundaries of innovation. Currently, I am focused on deepening my knowledge and skills in web development, data visualization, and game/engine development to enhance my visibility in the industry. My toolset includes Java, J2EE, Spring Technologies, and I'm equally proficient in frontend and backend development with technologies like PHP, Node.js, and modern frameworks such as React, Vue.js, and Angular. Effective communication is key to my workflow, ensuring clear and productive interactions with both technical and non-technical colleagues. I am naturally inquisitive and quick to adapt, always eager to explore new technologies and tackle the next challenge. My approach to projects is methodical and efficient, which allows me to exceed expectations and meet deadlines consistently. Areas of Expertise: Programming Languages: Java, J2EE, Spring: Deep expertise in building robust backend applications. PHP, Node.js: Skilled in dynamic server-side development. JavaScript (Angular, React, Vue.js): Proficient in creating interactive and responsive client-side interfaces. Python: Proficient in Python programming, emphasizing automation, data analysis, and backend solutions. Web Development: Skilled in a broad range of web development techniques and technologies, catering to both frontend and backend needs. Others: C, C++, RESTful and SOAP APIs, SQL, Hibernate, Maven, Gradle, Microservices. Web Development: WordPress: Advanced experience in developing and managing websites, enhancing user experience and site functionality. Full Stack Development: Comprehensive ability to handle both frontend visuals and backend functionality seamlessly. Soft Skills: Communication: Excel at articulating project goals and technical details clearly, ensuring all team members are aligned. Initiative and Agility: Motivated by new challenges, I approach projects with enthusiasm and a readiness to innovate. Time Management: My projects are not only completed within deadlines but also with a quality that often surpasses expectations. I'm excited about the future projects and opportunities that lie ahead, and I'm always looking for ways to contribute to and learn from the vibrant tech community here in California.

Java
Amazon Web Services
Web Application
React
Angular
Node.js
RESTful API
C++
Spring Boot
J2EE
Kotlin
SQL
JavaScript
Python
$167 hourly
- 4.9/5
- (12 jobs)
I am a Computer Science Professor at Drexel University College of Computing and Informatics, where I received my PhD in Computer Science. I'm here to broaden my network and try out the world of freelancing. I am also an AI educator and consultant. Check out my YouTube channel @Prof-Reza to learn more about Artificial Intelligence and the new wave of Generative AI. I am passionate about designing trustworthy and effective interaction techniques for Human-AI collaboration. My research focuses on how humans build trust toward Embodied Virtual Agents (EVAs). I have collaborated with MIT Media Lab, CMU HCII, Harvard University, and UCSD, publishing in venues such as Springer Nature, ACM, and IEEE. I have been recognized as an Outstanding Reviewer by ACM ICMI 2019 and ACM CHI 2021. My work has been featured by multiple news outlets including The Next Web, TechXplore, and CBS News.

Java
Tutoring
Writing
Mathematics
Management Skills
Design & Usability Research
Artificial Neural Network
Algorithm Development
Website
Mathematics Tutoring
Artificial Intelligence
Neural Network
C++
Desktop Application
$67 hourly
- 5.0/5
- (20 jobs)
The two-second version: Oracle-trained engineer with 5+ years of software experience, impacting millions of users globally. Built cloud services powering industry giants and praised for top-tier project delivery. Clients say: 'Andrew is an expert of the highest caliber.' Ready to bring Fortune 500 expertise to your next project? Let’s create something extraordinary. -------- The longer, sit-down version: Pleasure to meet you! I'm Andrew. Most clients enjoy working with me because of my cheerful demeanor, prompt communication, and ability to build productive relationships where they feel better off after collaborating with me. I’m passionate about delivering results that exceed expectations while making the experience enjoyable and professional. As a skilled Software Engineer with over 5 years of experience, including a pivotal role at Oracle (Fortune 500), I’ve built scalable solutions that have impacted millions of users globally. I bring a deep understanding of cloud services, web/mobile development, and DevOps, delivering high-impact results. 💡 Key Achievements: •Developed managed cloud services like OpenSearch and Redis at Oracle, powering critical workloads. •Played a key role in building healthcare services (FHIR), delivering in time for audit deadlines, supporting thousands of users. ⭐️ Client Testimonials: • "Andrew is an expert of the highest caliber. He delivered a custom-built webpage that exceeded my expectations." • "Very good communication, delivered on time. It was nice working with him!" 💼 How I Can Elevate Your Project: •Web Development: Expert in JavaScript, React.js, Node.js, Python, and more •Mobile Development: Proficient in Java, Kotlin, Swift, and Flutter •Cloud & DevOps: Extensive experience with AWS, Azure, GCP, and Oracle Cloud •Database Management: Skilled in MySQL, PostgreSQL, MongoDB, and Oracle DB •API Integration: Specialized in RESTful APIs, OpenAI, Stripe, Elasticsearch, and Redis, Rentec, Real Estate Software, Twilio 🌟 Why Choose Me: • Fortune 500 Expertise: Built cloud services used by millions. • Versatile Skill Set: Full-stack development, cloud infrastructure, DevOps, mobile development. •Client-Centric Approach: Focused on clear communication and exceeding client expectations. •Proven Results: Consistently delivered high-quality work on time and within budget. 📩 Let's connect and discuss how I can help turn your ideas into reality. Whether you're a startup looking to launch your first product or an established company seeking to modernize your tech stack, I'm ready to bring my Fortune 500 expertise to your project and create something extraordinary together!

Java
Back-End Development
Full-Stack Development
Web Application
Web API
Database
iOS Development
WordPress
API Integration
HTML
Python
Desktop Application
Android App Development
Python Script
ChatGPT
$150 hourly
- 4.8/5
- (80 jobs)
Automated Strategy, Indicator, Add-on, Custom Tools, I do them all! With 5 years intensive experience I am an expert in these areas and will guarantee you project completed to your liking or your money back. I am also a Trader too, so say goodbye to the days of trying to explain something to a developer that they don't understand

Java
Microsoft PowerApps
Microsoft Power Automate
Bot Development
MQL 5
Automation
NinjaTrader
MQL 4
Software Development
Scripting
C#
JavaScript
Python
HTML
CSS
$35 hourly
- 5.0/5
- (6 jobs)
🎖 Senior Mobile App Engineer 🎖 Experienced Flutter/Flutterflow Developer 🥇 Experienced Android developer 🥇 Android WearOS App developer 🎖 Experienced React Developer 🎖 Experienced UI/UX Designer My Work rules: ✅ Clean code: Well written and structure code (clean architecture) ✅ Reusable, readable and optimized for team ✅ Built with security and scalability: planned in scalability to grow as you as business expands without extra cost. Ecosystem i have worked for: 🔸 Bank 🔸 Fintech. 🔸 Job board 🔸 Real estate. 🔸 Edtech estate. 🔸 Blockchain Tech & Motto Skills: - Proficient in Git, CICD, JIRA, UI/UX, and Figma - Knowledgeable in testing (unit, widget, integration) in Flutter - Strong problem-solving skills and attention to detail - Fast response and good team spirit - Experienced in developing mobile apps for both iOS and Android platforms using Flutter - Familiarity with Agile methodology Technologies: *️⃣ Native Android, *️⃣ JAVA & Kotlin. *️⃣ Flutter, *️⃣ Node.js,Typscript, Express, mongodb *️⃣ Figma, XD, Penpot *️⃣ Notification (FCM & OneSignal) *️⃣ SQLite, *️⃣ Firebase, Supabase, *️⃣ Authentication *️⃣ API development, cloud functions, *️⃣ API Rest & GraphQl, *️⃣ Springboot & Express JS 📲 IOT, ESP8266, Aduino powered App

Java
Spring Boot
FlutterFlow
Figma
Agile Project Management
RESTful API
Swift
Android
GitHub
GraphQL
Dart
Flutter
$35 hourly
- 5.0/5
- (4 jobs)
My name is Jalen Morgan and I am currently a Cyber Officer in the US Army. Armed with expertise in numerous programming languages such as C/C++, Scala, Java, Python, Javascript, HTML/CSS and even bash scripting, Network Security and Incident Response, I have a broad range of skills. My academic background includes a B.S. in Computer Science and proven contributions to the OpenWPM project. As a collaborative team player, I adapt seamlessly to dynamic challenges and showcase a track record of achieving tangible results.

Java
System Administration
Redux
Node.js
React
JavaScript
Bash
Digital Forensics
C++
C
Machine Learning
Scala
Python
Computer Science
Information Security
$45 hourly
- 5.0/5
- (5 jobs)
A full stack developer. Here to help with front and back end web development. Experience working with JavaScript, React, PHP, SQL, among other skills.

Java
WordPress Plugin
Vue.js
Python
SQL
PHP
TypeScript
jQuery
JavaScript
HTML
React
Node.js
WordPress
CSS
$56 hourly
- 4.5/5
- (19 jobs)
I am a visual effects artist and 3D Compositor that has worked on various projects including motion picture and commercial work. I have experience in areas including object insertion, tracking, rotoscoping, chroma keying, color correction, simulations and much more in both live action and fully 3D environments. I have experience both working in large teams on projects as well as being the sole artist on multiple occasions. My workflow often includes applications such as After Effects, Cinema4D, Redshift, X-Particles, Mocha, and Red Giant Suite for VFX as well as Adobe Audition for sound effects when necessary.

Java
Animated Environment
Visual Effects
Compositing
Audio Effects
Adobe Photoshop
Green Screen
Adobe Inc.
Visual Art
Special Effects
Keying
Animation
Adobe Premiere Pro
Maxon Cinema 4D
Adobe After Effects
$70 hourly
- 5.0/5
- (1 job)
👋 5+ years as a web dev. I build static websites and custom web applications for your business. My experience covers Front-end dev in React, Astro, Javascript, Tailwind CSS, HTML5/CSS3 and Back-end dev in web servers using Node.js, Express.js.

Java
React
Back-End Development
Front-End Development
Front-End Development Framework
Emerging Tech Consultation
AI Consulting
Blockchain
Node.js
JavaScript
$80 hourly
- 4.6/5
- (5 jobs)
Over 10 years of experience in backend, mobile, desktop, and cross-platform development with a myriad of languages & platforms for major software companies in the bay area and around the world. Strong background in advanced algorithms, data structures & high-performance multithreading. Specialization in advanced build tooling including Bazel, Buck & Pants, and a leading Bazel community expert with proven expertise in porting many millions of lines of code to build & test with Bazel.

Java
Buck
Golang
Build Automation
Reactive Programming
Android SDK
iOS Development
Kotlin
Scala
Swift
C++
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