Upstaff Developer Profile Directory
All vetted software engineers you need to build AI, Web3, and data Products.
- Dedicated Full-time commitment for long-term or Time& Material for shorter or ongoing support
- Europe, Israel, LatAm, United States, Asia geography coverage
- Remote and hybrid engagement
- Trial period, no termination fees or hidden costs for transparent and risk-free onboarding.
All
All
Web Application
Data and Analytics
Cloud and Operations
Mobile Application
Digital Platforms
Blockchain
Design and Creative
Quality Assurance
Project Management
Desktop Application
Writing and Translation
Scripting and Automation
Marketing and SEO
Embedded Systems
Low-Code and No-Code
GameDev
Industrial Engineering
PHP 6yr.
Python 5yr.
Django REST framework 5yr.
Node.js 4yr.
- Experienced software engineer with over 12 years in the IT industry, specializing in system architecture, full stack development, and cloud deployment, predominantly in AWS.
- Strong proficiencies in backend technologies including Python, PHP, Node.js, Java, and web frameworks such as Django, Laravel, and CakePHP.
- Demonstrated experience with both SQL and NoSQL databases, adhering to best practices in database management and data-driven application development.
- Proficient in orchestration tools like Kubernetes and Docker, enabling efficient CI/CD pipelines and application deployment.
- Recognized for academic excellence with a Master’s in Applied Software Development and awards such as 'Student of the Year'.
- Proven track record of leading and completing complex projects, reflected in an extensive project portfolio encompassing various domains and technologies.
C/C++/C#
JavaScript
Python
ASP.NET MVC
Blazor
Software engineering professional with over 14 years of experience in full-stack development. Versed in a range of technologies including C#, JavaScript, Python, .NET Core, and cloud services like Azure. Proven capability in leading teams and optimizing applications, achieving up to a 40% improvement in performance metrics. Holder of relevant certifications like Azure DevOps Engineer Expert and Azure Administrator Associate. Recognized for exceptional contributions with multiple awards, showcasing a commitment to innovation and excellence in software delivery within the IT industry.
Reverse Engineering
React Native
Android APIs
iOS
• 6+ years of experience in reverse engineering and security analysis of iOS and Android applications, including authentication, password reset, OTP, and account recovery flows;
• Experience with static and dynamic analysis using Frida, JADX, IDA/Ghidra, Hopper, Burp Suite, and mitmproxy, including hooking runtime behavior, traffic interception, and analysis of obfuscated code paths;
• Understanding of network protocols, API behavior, session handling, token flow inspection, and secure communication patterns in mobile systems;
• Skilled in bypassing anti-debugging protections, inspecting native components, and analyzing undocumented logic in React Native, Swift, Kotlin, and mixed-architecture apps;
• Experienced of mapping complex authentication workflows, documenting mobile security mechanisms, producing technical reports, diagrams, and vulnerability-focused flow descriptions;
• Experience optimizing backend/mobile integrated flows with PostgreSQL, caching, throttling, and performance tuning in high-load financial and administrative mobile apps;
• Skilled in mobile application security analysis across fintech, art commerce, and critical operations platforms, including real-time traffic inspection and security hardening;
• Effective communicator with experience collaborating with product, operator, and engineering teams through RFCs, status updates, and structured documentation.
React 2yr.
TypeScript 2yr.
JavaScript 2yr.
HTML5 2yr.
CSS3 2yr.
Software engineer with a solid foundation in front-end development, expertly handling React, TypeScript, and JavaScript (ES2015-2019). Proven experience in deploying robust web applications using Redux, Zustand, and state-of-the-art web technologies. Demonstrates a keen eye for UI/UX design implementing Figma creations into functional user interfaces, coupled with strong backend competencies in Node.js, PostgreSQL, and MySQL. Adept at utilizing development tools such as Git/GitHub, VS Code, and NPM for efficient project management and collaboration. Brings a strong work ethic and problem-solving skills to development teams, with a history of driving project success from conception to deployment.
React 6yr.
Redux-Saga 4yr.
Styled components 4yr.
Angular 4yr.
Vue.js 4yr.
An accomplished front-end engineer with a solid foundation in Computer Science from UNAD University and over 6 years of professional experience, including 4 years as a Senior Front-End Developer at Adastra. Demonstrates advanced proficiency in React.js, Redux-Saga, Vue.js, Angular.js, and modern web development with a proven track record of leading the development of scalable, responsive, and high-performance web applications. Notable achievements include spearheading a migration to microservices architecture, yielding a 40% reduction in system downtime. Possesses in-depth knowledge of cloud services (AWS), CI/CD methodologies (Jenkins), and containerization (Docker). The engineer's programming toolkit encompasses a diverse set of languages and utilities such as Typescript, Docker, and Node.js, as well as experience with blockchain technologies like Solidity and web3.js, enabling the delivery of comprehensive end-to-end web solutions.
Java
- Have experience in programming Spring Framework.
- Have experience with Microservices architecture.
- Practice with Elasticsearch (Kibana);
- Experience in the fintech sphere;
- Understanding of “Clean code”;
- Good logical thinking, self-learning, high level of responsibility.
- Responsible, hard-working, result-oriented, creative, and communicative, team player.
- Intermediate English.
- Availability starting from Asap
AQA Engineer 5yr.
- Experienced AQA Engineer with 4 years of expertise in web, API, and performance testing.
- Proficient in manual testing, requirements analysis, and writing test documentation.
- Skilled in various programming languages including JavaScript, TypeScript, Python, and Java.
- Familiar with a wide range of tools and technologies such as GitHub, Azure, Selenium, Cypress, and Jira.
- Strong knowledge of software development life cycle and Quality Assurance methodologies.
- Experienced in test automation at different levels using technologies like Playwright, Jest, and Docker.
- Excellent communication and problem-solving skills, with a strong ability to prioritize and coordinate testing activities.
C# 6yr.
.NET 6yr.
API testing
UI testing
- Software Test Automation Engineer with 6+ years of experience with knowledge and hands-on experience in UI and API test automation
- Experienced in the next practices: Raising Efficiency of Test Automation, Test Automation Approaches, Development in .NET ecosystem (Test Automation), Test Automation Framework Architecture, GUI Testing, Web Service / API Testing, Testing Fundamentals, Quality Gates, Component / Integration Testing;
- Good knowledge and practical skills in C#, Selenium, Coded UI, MSTest (v1 & v2), TFS, Azure DevOps, Azure Cloud, YAML pipelines and custom C# solutions
- Experience in API Performance testing; custom solution was created from scratch in C# .NET Core
- Hands-on experience in designing Test Cases, Test Suites, and Bug Reports, as well as identifying issues
- Experience in designing and implementing automated tests and test results analysis
Manual QA
QA Automation
Senior Automation QA Engineer with over 5 years of experience in the software industry;
- Proficient in Atlassian tools (Jira, Confluence, Stash, Bamboo) ;
- Skilled in automation testing using Java, Selenium, WebDriver, Selenide, XPath, CSS, JUnit, TestNG, Maven, and Gradle;
- Strong background in API and UI automation, with expertise in developing automation frameworks from scratch;
- Experienced in continuous integration and deployment using tools like TeamCity and Jenkins;
- Knowledgeable in load and performance testing using Apache JMeter;
- Experienced in using version control systems like Git;
- Familiar with databases like MySQL, Mongo, and ClickHouse.
Test Automation 17yr.
Mihai Serdean is a software engineer with 17 years of experience in IT software and QA. He is currently working as a freelancer in software quality assurance and is part of various freelance networks such as Toptal, Upper, Expertlead, and WorkGenius. Mihai has expertise in test automation, performance testing, and using tools such as Selenium WebDriver, Cypress, JMeter, and Postman. He is skilled in multiple programming languages including Java, JavaScript, TypeScript, Python, and .Net. Mihai has a strong background in computer science, holding both a Master's and Bachelor's degree from Universitatea "Babeș-Bolyai" din Cluj-Napoca. He has experience in implementing QA strategies, managing QA teams, and improving QA processes. Mihai has worked with various companies and has a track record of delivering high-quality software solutions.
AWS Security Groups 2yr.
GCE 1yr.
Data Analysis
FreeBSD
This software engineer boasts hands-on experience in cloud technologies, data analysis, and information security, supported by a BSc in Computer Science. Expert in Microsoft security and AWS cloud services, they have effectively managed projects in cloud computing, setting up and monitoring AWS resources with a focus on automation. With proficiency in cybersecurity principles, identity management, and threat protection, their skill set extends to serverless computing, data visualization, and network security. They demonstrate an advanced command of technical tools including CloudWatch, Power BI, and SQL, showcasing the capability to implement data-driven solutions. Their work experience encompasses providing IT support and deploying cloud solutions, evidencing a strong track record in both the educational and corporate sectors. Holding numerous industry certifications, this engineer embodies a blend of technical acumen and practical experience, making them a standout candidate for roles prioritizing cloud infrastructure and cybersecurity.
.NET
- 10+ years of experience in full-stack .NET development across fintech, healthcare, insurtech, and SaaS domains;
- Expertise in backend engineering with .NET Core/.NET Framework, microservices, high-load systems, and cloud-native architectures (Azure, AWS);
- Full-stack experience with React.js, REST/SOAP services, Web API, and Windows Services;
- Experienced with MS SQL, PostgreSQL, MongoDB, Oracle, Redis, and Elasticsearch, including performance optimization and reliable data-driven solutions;
- Skilled in distributed systems using Kafka, Docker, and modern CI/CD practices via Azure DevOps;
- Experienced in integrating external systems, building scalable APIs, and delivering complex enterprise workflows for banking, CRM, and healthcare platforms;
- Strong background in Agile/Scrum, TDD, cross-functional collaboration, and architecture decision-making;
- Solid foundation in C#, JavaScript, SQL, and cloud services (Azure Functions, CosmosDB, Blobs, AWS S3).
JavaScript
TypeScript
React
Redux
Next.js
Software engineer specializing in scalable React applications, with a robust engineering background in microelectronics and applied physics. Experienced in working with international teams, the engineer boasts a track record of successful frontend development across EdTech and enterprise domains. Notable technical competencies include mastery of JavaScript (ES6+), TypeScript, React.js, Next.js, and performance optimization. Key achievements include A/B Testing for UX enhancement, leading API integrations and performance boosting initiatives. Armed with Agile methodologies, the candidate has effectively communicated and coordinated within cross-functional teams. With a solid foundation in computer science education and hands-on experience, this candidate is a fit for roles requiring deep technical expertise and a commitment to high-quality, efficient software development.
C/C++/C# 11yr.
ASP.NET Core Framework 5yr.
.NET Maui 1yr.
React
JavaScript
Seasoned full-stack .NET developer with over 11 years' experience specializing in C# and ASP.NET Core application development. Proven track record in building scalable and reliable applications across healthcare, logistics, and financial industries. Expertise in database optimization with MSSQL and implementing RESTful APIs, marked by success in creating responsive web interfaces enhanced with technologies like ReactJS and TypeScript. Holds certifications in ASP.NET Core and Angular app development, as well as SAP Business One. Adept in Agile methodologies and CI/CD practices using Azure DevOps.
JavaScript 6yr.
TypeScript
NestJS
Engineer with 6 years of experience specializes in back-end development, architecture, and optimization. Proficient in JavaScript, TypeScript, Python, Node.js, and a suite of modern database technologies. Delivered complex projects, including multi-tenant SaaS platforms and event management systems. Holds a BE in IT with a strong grasp of Agile SDLC and coding best practices. Demonstrated skills in AWS, RESTful APIs, and both SQL and NoSQL databases, with a track record of mentoring teams and driving engineering excellence.
WordPress 5yr.
Shopify 3yr.
Wix 3yr.
Ant Design
A proficient web developer with years of practical experience, specializing in creating robust websites using WordPress, Wix, and Shopify. Has a strong foundation in Computer Science with a BS degree from DHA Suffa University. Highly skilled in website design, evidenced by a history of successfully freelancing in the domain. Demonstrates a clear understanding of software development practices and the SDLC. Technically adept in numerous aspects of web development including graphic design and WordPress theme customization, this candidate has a proven track record with companies like Omar Technologies and Dracarys Developers, bringing to the table a blend of technical expertise and pragmatic problem-solving abilities.
Node.js
Express
MongoDB
RESTful API
Unreal Engine
Backend Engineer with proven expertise in scalable and secure products using Node.js, Express.js, and MongoDB. Demonstrates technical proficiency in building RESTful APIs, integrating payment services like Paystack, and deploying robust authentication systems. Engages in content creation, sharing backend tutorials while also fostering a community of developers. Holds a bachelor's degree in Environmental Education with further specialization in backend engineering through a diploma. Proven track record in problem-solving and product enhancement within a collaborative team in the travel industry. Key projects include a full-stack Blog Authentication System and a Wallet Transaction System, showcasing proficiency in Node.js, Express, MongoDB, and JWT.
React 5yr.
Redux-toolkit
Ext JS
Node.js
Express
Software engineer with 5 years of experience specializing in full-stack development, adept in both front-end and back-end technologies. Key skills include mastery of React.js, Redux Toolkit, Node.js, Express.js, and familiarity with modern frontend frameworks. Proven track record of driving innovation and handling complex problems, demonstrated by achievements such as the AI-driven navigation bar and data analysis in computational notebooks at BetterBrain. Expert in enhancing user experiences, improving operational efficiency by 30%, and mastering data management solutions. Academic background supported by a Bachelor's degree in Computer Science and continuous professional development through courses. An engineer proficient in SDLC, agile methodologies, and modern development practices, ready to deliver top-tier web applications.
React 1yr.
CodeIgniter 1yr.
MySQL 1yr.
JavaScript 1yr.
HTML5
Versatile Junior Developer with expertise in React.js, Core PHP, CodeIgniter, MySQL, and JavaScript, along with a solid foundation in database systems and software engineering from B.Tech in Computer Science. Demonstrated skills in developing dynamic web applications, implementing CRUD operations, and designing secure API integrations. Proven ability to work collaboratively in team environments, paired with a commitment to maintaining high-quality standards in line with CMMi guidelines. Recognized for efficiently handling client requirements, troubleshooting issues, and mentoring junior team members. Portfolio includes building a multilingual import-export platform and a finance tracking app. Holds a Full Stack Developer Certification, showcasing proficiency in modern web technologies.
C++
Linux
- 7 years of experience in C/C++ software development with a focus on embedded and firmware systems;
- Expertise in Linux-based environments, networking, and system-level programming, including DHCP, DNS, ARP, and VoIP;
- Skilled with OpenWRT, Buildroot, U-Boot, and debugging tools such as GDB, Valgrind, Wireshark, and tcpdump;
- Experience in WiFi 6 and LTE/5G SA/NSA gateway development, performance optimization, and legacy code refactoring;
- Knowledge of CI/CD (Jenkins), scripting (Bash), and virtualization (QEMU);
- Skilled in team management, code review, and process improvement, ensuring product quality and delivery efficiency across all project phases.
Angular
TypeScript
.NET
JavaScript
RxJs
Expert with Angular, Typescript, Javascript, RxJs, enteprise level applications.
Currently learning React and Next.js framework
PHP
JavaScript
jQuery
MySQL
PostgreSQL
Expert software engineer with 20+ years of experience specializing in backend and full-stack development. Proficient in an array of languages like PHP, Visual Basic, and JavaScript, with a strong foundation in database architecture across MySQL, PostgreSQL, and SQL Server. Demonstrates a consistent track record of optimizing system performance and scalability, evidenced by a 40% reduction in load times and a successful migration from Delphi to PHP. Holds an engineering degree and numerous technical certifications, underpinning a solid educational foundation in computer science. Recognized for advanced technical skills and delivering high-impact projects such as ScanChex Mobile and comprehensive payroll and administrative systems.
React
JavaScript
TypeScript
RESTful API
Redux
With over half a decade of experience, the engineer stands out as a seasoned React Developer who possesses a deep understanding of front-end technologies including ReactJS, NextJS, JavaScript, and Typescript. An adept professional in employing Rest APIs, Redux, and various CSS frameworks such as Material UI and Tailwind for creating responsive and user-friendly interfaces. The engineer's portfolio includes significant contributions to diverse domains like Social Networking, AgriTech, and IT Services, which showcases versatility and technical acumen. Leveraging a strong background in the entire software development life cycle, the engineer has a proven track record in implementing CI/CD pipelines and maintaining code versions using Git, demonstrating an expertise that optimizes application features and ensures delivery of high-quality software products.
Python
PostgreSQL
SQLAlchemy
- 8+ years of experience in backend development with a strong focus on Python and distributed systems.
- Expertise in Django, FastAPI, and Flask, including experience building and optimizing microservices architectures.
- Skilled in designing and maintaining REST APIs and GraphQL services for large-scale telecom, healthcare, and e-commerce platforms.
- Deep understanding of PostgreSQL, SQLAlchemy, and MySQL, with experience in database design, optimization, and performance tuning.
- Skilled in Docker and Kubernetes for containerization and orchestration, as well as CI/CD pipelines setup using Jenkins.
- Experienced in asynchronous programming and real-time systems development.
- Strong knowledge of OOP, SOLID, and design patterns, with experience implementing secure and testable backend code.
- Worked with AWS (EC2, RDS, S3) and Azure AD B2C for authentication and cloud infrastructure management.
- Background in AI integration, data encryption, and authorization systems for enterprise-grade software solutions.
C++
Qt Framework
Python
PostgreSQL
- 7+ years of experience in C++ software development across desktop and embedded systems;
- Experienced with 15+ commercial projects in automotive, fintech, and embedded domains;
- Skilled in C++, Qt, QML, Python, and experience with JavaScript, Lua, and TypeScript for cross-platform applications;
- Skilled in REST API, HTTP, VoIP, SIP, and DICOM integrations;
- Experience with GitLab, Jenkins, Azure, TFS, SVN, CodeBlocks, QtCreator, and Visual Studio across Windows, Linux, and Mac environments;
- Solid understanding of SDLC, clean architecture, software optimization, and code refactoring for performance and maintainability;
- Experienced in mentoring team members, code reviews, and ensuring adherence to best engineering practices.
JavaScript 1yr.
React 1yr.
Node.js
Express
TypeScript
Frontend Developer with over 1 year of self-led learning and 9+ months of hands-on project experience. Expertise in JavaScript, TypeScript, React.js, and Python. Proficient with backend technologies such as Node.js, Express.js, and NestJS, including RESTful APIs and database management using PostgreSQL and Firebase. Demonstrated ability in deploying web applications with tools like Render and CI/CD practices. Strong focus on responsive design, accessibility, and performance optimization, underpinned by knowledge of modern development methodologies and design patterns.
React 3yr.
Node.js 3yr.
MySQL 3yr.
NestJS
Sequelize
Seasoned Full-stack Developer with a comprehensive understanding of both front-end and back-end technologies, proficient in React, Node.js, and NestJS. Brings over 3 years of commercial experience in creating web applications and automation bots, with a proven track record of optimizing performance and enhancing prompt designs for LLMs resulting in a 30% quality improvement. Demonstrated success in scalable solution development with a focus on efficiency, evident from a 40% MySQL query performance enhancement. Holds solid DevOps fundamentals with hands-on experience in Docker, Git, CI/CD, and a diverse tech stack encompassing Sequelize ORM, Python, and various LLM APIs. Proactive problem-solver and an advocate for clean code practices, geared with a strong education in technology, highlighted by a notable GPA from AEH. Eligible to work in the EU, multilingual with proficiency in English, Polish, Russian, and Belarusian, and with a future plan to potentially shift base to Düsseldorf in 2026.
Python
PostgreSQL
SQLAlchemy
- 5+ years of experience in Python backend development, focused on distributed systems, REST API design, and microservice architecture;
- Experienced with FastAPI, Django, and Django REST Framework, with a deep understanding of framework internals and asynchronous programming (asyncio, Celery, Kafka);
- Experience developing and maintaining scalable APIs and high-performance backend services for AI-driven platforms, cryptocurrency systems, and automation tools;
- Solid knowledge of RDBMS systems with emphasis on PostgreSQL - database schema design, optimization, and query performance tuning;
- Experience with SQLAlchemy (declarative and async modes) and integration of data pipelines across multiple services;
- Skilled in Docker-based deployments and cloud environments (AWS, Azure) with hands-on CI/CD setup and monitoring;
- Experienced in secure authentication systems (JWT, OAuth2) and real-time data streaming using Kafka and Celery;
- Strong command of SDLC, code quality, testing (Pytest), and Agile methodologies;
- Experience in AI integration - building and deploying AI agents and workflow automation tools with LangChain, Supabase, and Firebase.
Expertise in C/C++ 4yr.
Bash 4yr.
Go 3yr.
GitHub
Linux
A seasoned software engineer with extensive experience in developing, maintaining, and testing systems, particularly with the Open Source SONiC OS at Nokia. Proficient in a wide range of programming languages including Rust, C/C++, Python, TypeScript, Lua, and scripting with Bash. Demonstrated expertise in Linux kernel development, network protocols, containerization with Docker, and CI/CD pipelines using Gitlab. Contributed significant automation improvements through tools like Ansible, Prometheus, and Grafana. Additionally, has a background in service desk support with a focus on Azure and Active Directory, and demonstrates ongoing commitment to professional development as shown by their technical degree from Hive Helsinki, with a strong foundation in algorithms, network programming, and game development.
Quadient Inspire 5yr.
React Native 3yr.
React 3yr.
relational databases
- Full Stack Developer with 5+ years of experience building and scaling web & mobile applications using the MERN stack, React Native, and DevOps practices, including Docker, CI/CD, and AWS.
- Adept at designing, developing, and deploying production-ready MVPs for various clients, with a record of 25+ successful product launches.
- Proficient in React.js, such as employing advanced state management with Redux and React Context, and optimizing performance with best practices like lazy loading and code splitting.
- Technical writer and educator with content reaching over 700K readers, contributing to freeCodeCamp and other tech platforms, enhancing knowledge sharing within the developer community.
- Holds a BTech in Computer Science, providing a solid foundation in software engineering principles; experienced in collaborating with design teams to create fluid, responsive UI/UX for web applications.
- Demonstrates a deep understanding of software development life cycle and modern development methodologies, as well as a knack for teaching coding and assisting clients with SEO and organic growth.