Team Lead FullStack (Node.js, React)

🏢 Summary: Senior Full Stack Developer role focused on architecting and delivering high-performance web applications using React and Node.js. The position involves leading system design, building scalable front-end and back-end solutions, and overseeing cloud-based deployments and DevOps processes. The role includes technical ownership of microservices, APIs, databases, and application performance in a hybrid Warsaw-based setup. 🗂️ Requirements: 7+ years full stack development experience, 2+ years in senior or technical lead role, Expert-level React.js with Hooks and Redux, Advanced JavaScript ES6+ proficiency, Strong Node.js and Express.js experience, Experience designing REST or GraphQL APIs, Experience with OAuth, JWT, sessions, RBAC, Database design and optimization with PostgreSQL, MySQL, or MongoDB, Hands-on Docker experience, Experience with AWS, Azure, or GCP, CI/CD pipeline management experience, Proficiency with Git workflows, Bachelor’s or Master’s in Computer Science or related field 📃 Skills: React, Redux, JavaScript, HTML5, CSS3, Node.js, Express, GraphQL, REST, OAuth, JWT, RBAC, PostgreSQL, MySQL, MongoDB, Docker, Kubernetes, AWS, Azure, GCP, Git, CI/CD, Webpack, Babel, Vite 🏢 Description: 🧩 About the Company Our client is a rapidly growing US-based technology firm with global operations. With a strong commitment to innovation and quality engineering, the company is building a new engineering hub in Warsaw. This is your opportunity to join a high-performing team and play a pivotal role in developing next-generation digital solutions for the private capital markets. 📍 Location & Setup Start remotely and transition to a hybrid model based in Warsaw (3 days/week in the office in the coming months). 🧠 The Role: Senior Full Stack Developer (React & Node.js) We’re looking for an expert-level Senior Full Stack Developer with at least 7 years of professional experience in designing, architecting, and delivering high-performance web applications. You will take ownership of complex technical challenges across both the front-end and back-end, drive architectural decisions, and provide technical leadership and mentorship within the software development lifecycle. 🔧 Key Responsibilities Technical Leadership: Architect and develop scalable, responsive UIs with React.js, Redux, and modern JavaScript (ES6+). System Design: Design, build, and scale advanced server-side applications, microservices architecture, and RESTful/GraphQL APIs with Node.js and Express. Data Architecture: Lead database design, optimization, and integration strategies (PostgreSQL, MySQL, or MongoDB). Quality Assurance: Define testing strategies, write robust unit/integration tests, and establish efficient debugging protocols for the team. DevOps & Deployment: Oversee and optimize CI/CD pipelines, containerization using Docker, and cloud deployments. Agile Mentorship: Lead agile collaboration with product managers, designers, and engineers, while mentoring mid-level and junior developers. Performance: Proactively monitor system performance, identify bottlenecks, and maintain high-availability production-grade applications. Standards: Establish and maintain comprehensive technical documentation and coding standards. 📌 What We’re Looking For Front-End: Expert-level experience with React.js, Hooks, Redux, and complex component-based architecture. Deep mastery of HTML5, CSS3, and ES6+. Advanced configuration and optimization experience with build tools like Webpack, Babel, or Vite. Back-End: Senior-level proficiency in Node.js & Express.js for enterprise applications. Extensive API design and architecture experience (GraphQL highly preferred, alongside REST). Deep understanding and implementation experience with advanced security and authentication protocols: OAuth, JWT, sessions, and RBAC. Databases & DevOps: Proven experience in scaling and optimizing relational and non-relational databases (PostgreSQL, MySQL, or MongoDB). Solid hands-on experience with Docker; Kubernetes experience is highly advantageous. Demonstrated experience designing and deploying applications on cloud platforms (AWS, Azure, or GCP). Advanced proficiency with Git workflows and driving Agile/Scrum methodologies. 🎓 Qualifications Bachelor’s or Master’s in Computer Science or a related field. 7+ years of hands-on experience in full stack development. 2+ years of experience in a senior or technical lead capacity. Proven track record of architecting, deploying, and maintaining high-traffic production applications. 💡 Soft Skills Strategic, analytical thinker and highly effective problem-solver. Strong technical leadership, team collaboration, and cross-functional communication skills. Self-motivated with excellent time management and the ability to drive projects autonomously. Passion for continuous learning, adopting new technologies, and sharing knowledge with the team. 🎁 What’s Offered Competitive salary up to $6,200 USD/month. Hybrid remote role with 3 days form office in the heart of Warsaw Generous Paid Time Off (PTO). Comprehensive full benefits package. The unique chance to shape the technical foundation of a new engineering hub and lead high-impact projects. A supportive, innovation-driven work environment that values technical excellence.

🏢 Summary: Senior Full Stack Team Lead role focused on building and scaling web applications using React and Node.js while leading a development team. The position combines hands-on front-end and back-end development with architecture design, API development, and deployment in cloud environments. You will drive technical decisions, ensure code quality, and oversee delivery of scalable, production-ready systems. 🗂️ Requirements: 7+ years full-stack development experience with React and Node.js, 2+ years experience in leadership or senior technical role, Strong experience with React.js, Redux, React Hooks, Strong knowledge of HTML5, CSS3, modern JavaScript, Proficiency in Node.js and Express.js, Experience building REST APIs, Experience with PostgreSQL or MySQL, Experience with authentication methods (OAuth, JWT, sessions), Experience with CI/CD and Docker, Experience working with production systems, Experience with Git, Understanding of Agile/Scrum methodologies 📃 Skills: React, Redux, JavaScript, HTML5, CSS3, Node.js, Express, REST, GraphQL, PostgreSQL, MySQL, OAuth, JWT, Docker, Kubernetes, AWS, Azure, GCP, Git, CI/CD, Webpack, Babel, Vite, MongoDB 🏢 Description: Overview We are a leading company in AI-based enterprise operations. We provide digital solutions and consulting services that help businesses grow and improve. We use modern technology to make processes simpler, increase efficiency, and create new ways to earn money, especially in private capital markets. Our ecosystem includes three main parts. First, PaaS (Platform as a Service) with the Orion Platform, which helps improve workflows, show useful insights, and support value growth across portfolios. Second, SaaS (Software as a Service), a cloud platform that offers strong performance and smart tools at scale. Third, our Solutions and Consulting Suite, which includes flexible technology solutions to manage, grow, and improve company performance. With more than 10 years of experience, we support fast-growing companies and private equity platforms, turning technology into a real business advantage. Responsibilities and Duties We are looking for an experienced Full Stack Team Lead with strong skills in React and Node.js. The right person has over 7 years of experience building high-quality web applications and has experience leading a team. You will guide developers, work on both front-end and back-end, take part in all stages of development, and support junior team members. Key Responsibilities Team Leadership & Mentorship: Lead and support a team of developers. Help them grow, review code, and give technical advice. Front-End Development: Build and maintain user interfaces using React.js, Redux, and modern JavaScript. Back-End Development: Create strong and scalable server applications and APIs using Node.js and Express. Integration: Work with database engineers to design databases and manage data using MongoDB or SQL. Application Architecture: Design scalable systems and microservices that meet business needs. Testing & Debugging: Write tests, fix issues, and improve performance. Support good testing practices. Deployment: Manage releases using CI/CD tools and Docker. Collaboration: Work with designers, product managers, and developers to create useful solutions. Communicate with both technical and non-technical teams. Maintenance: Monitor systems, fix problems, and improve applications. Documentation: Write and maintain technical documents for systems and APIs. Requirements Front-End: Strong experience with React.js, Redux, React Hooks, and component-based design Good knowledge of HTML5, CSS3, and modern JavaScript Familiar with tools like Webpack, Babel, or Vite Back-End: Strong skills in Node.js and Express.js Experience building and using APIs (GraphQL is a plus, REST is required) Knowledge of authentication methods like OAuth, JWT, and sessions Database: Experience with PostgreSQL or MySQL Additional Skills: Experience with Docker and Kubernetes is a plus Knowledge of cloud platforms like AWS, Azure, or GCP Experience with Git Understanding of Agile/Scrum methods Qualifications At least 7 years of experience in full-stack development with React and Node.js At least 2 years in a leadership or senior role Experience working with live production systems Bachelor’s degree in Computer Science or similar (preferred) Soft Skills Strong problem-solving and analytical thinking Good communication and teamwork skills Ability to work independently and manage tasks well Willingness to learn new technologies and improve continuously Why Join Us? We look for people who solve problems creatively, learn quickly, and enjoy working in an open and diverse team. We work hard, but we also like to enjoy what we do and aim for high results.

🏢 Summary: Hybrid React Team Lead role focused on leading the development of scalable web applications and managing a frontend team in a dynamic, product-oriented environment. The position combines hands-on React development with architectural decisions, state management design, and close collaboration with cross-functional teams. It requires strong expertise in modern frontend technologies, testing practices, and performance optimization. 🗂️ Requirements: 5+ years experience with JavaScript/TypeScript, 3+ years experience with React.js, Strong knowledge of React Hooks, Strong knowledge of Context API, Strong knowledge of Redux (Redux Toolkit preferred), Experience with frontend design patterns, Experience with clean code principles, Experience with RESTful APIs or GraphQL, Good knowledge of HTML5, Good knowledge of CSS3/SCSS, Experience with responsive design, Experience with component libraries and design systems, Familiarity with Webpack or Vite, Experience leading or mentoring developers 📃 Skills: JavaScript, TypeScript, React, Redux, ReduxToolkit, Hooks, ContextAPI, HTML5, CSS3, SCSS, REST, GraphQL, Webpack, Vite, Jest, ReactTestingLibrary, Storybook, MaterialUI, Tailwind, Next.js, Lighthouse, ChromeDevTools, WCAG 🏢 Description: Please note: This is a hybrid role – 3 days per week from the office in Warsaw. Overview We are a leader in AI-powered enterprise operations. We deliver digital solutions and consulting services that help companies grow and improve their performance. We use advanced technology to simplify processes, increase efficiency, and create new business opportunities, especially in private capital markets. Our ecosystem includes: PaaS (Platform as a Service) – an AI-based platform that improves workflows, provides useful insights, and supports value creation across portfolios. SaaS (Software as a Service) – a cloud platform that offers strong performance, smart tools, and scalable solutions. S&C (Solutions and Consulting Suite) – modular technology solutions that help manage, grow, and improve company performance. With more than 10 years of experience working with fast-growing companies and private equity-backed businesses, we combine strong industry knowledge with technology expertise to create real business value. The Opportunity We are looking for an experienced and motivated React Team Lead to lead the development of modern and scalable web applications. You will manage a team of React developers, support good frontend architecture practices, and make sure we deliver fast and high-quality user interfaces. The ideal candidate has strong experience with React (including Hooks and Context API), Redux, and frontend design patterns. You should feel comfortable working in a dynamic and team-oriented environment. Responsibilities Lead, mentor, and support a team of React developers through code reviews, 1:1 meetings, and practical guidance. Work closely with product managers, designers, and backend engineers to plan and prioritize features. Manage sprint planning, task estimation, and delivery timelines for the frontend team. Design and build complex user interfaces using React, Hooks, and Context API. Develop and maintain scalable state management solutions using Redux Toolkit. Apply modern frontend design patterns (such as container/presenter, compound components, render props, and HOCs). Build reusable component libraries and ensure alignment with the design system. Improve application performance, accessibility, and cross-browser compatibility. Promote best practices in code quality, testing, CI/CD, and documentation. Maintain strong unit and integration test coverage (e.g., with Jest and React Testing Library). Support frontend architecture decisions and evaluate new tools when needed. Requirements 5+ years of experience with JavaScript/TypeScript, including 3+ years with React.js Strong knowledge of React Hooks, Context API, and Redux (Redux Toolkit preferred) Experience with frontend design patterns and clean code principles Experience working with RESTful APIs or GraphQL Good knowledge of HTML5, CSS3/SCSS, and responsive design Experience with component libraries and design systems (e.g., Storybook, Material UI, Tailwind) Familiarity with build tools such as Webpack or Vite Experience leading or mentoring developers Nice to Have Experience with performance tools (e.g., Lighthouse, Chrome DevTools) Experience with SSR/SSG frameworks like Next.js Knowledge of accessibility standards (WCAG) Contributions to open-source frontend projects Why Join Us? We are looking for creative people who solve problems, learn quickly, and enjoy working in an open and diverse environment. We work hard, support each other, and also make time to enjoy what we do.

🏢 Summary: Frontend Team Lead role focused on leading the development of scalable, high-performance React applications in a hybrid work model. The position combines hands-on architecture and implementation with mentoring a frontend team and enforcing best practices in design patterns, testing, and CI/CD. The role requires strong expertise in modern React ecosystem and state management to drive frontend excellence. 🗂️ Requirements: 5+ years experience with JavaScript or TypeScript, 3+ years commercial experience with React.js, Strong knowledge of React Hooks and Context API, Strong experience with Redux and Redux Toolkit, Experience with frontend design patterns and clean code principles, Experience integrating REST or GraphQL APIs, Strong knowledge of HTML5 and CSS3 or SCSS, Experience with component libraries and design systems, Familiarity with Webpack or Vite build tools, Experience with unit and integration testing, Experience leading or mentoring frontend developers 📃 Skills: JavaScript, TypeScript, React, Hooks, ContextAPI, Redux, ReduxToolkit, HTML5, CSS3, SCSS, REST, GraphQL, Webpack, Vite, Jest, ReactTestingLibrary, Storybook, MaterialUI, Tailwind, Next.js, Lighthouse, ChromeDevTools, WCAG, CICD 🏢 Description: Frontend Team Lead (React) 📍 Warsaw Poland, Hybrid remote with 3 days from office 💼 Contract of Employment / Umowa o pracę 💰 Monthly compensation up to 8,000 USD About the Client Our Client is a leader in AI-powered enterprise operations, delivering digital solutions and consulting services that drive value and transform businesses. They specialize in using advanced technology to streamline operations, improve efficiency, and unlock new revenue opportunities, particularly within the private capital markets. Their integrated ecosystem includes PaaS - Platform as a Service, the Core Platform, an AI-native enterprise operations foundation built to optimize workflows, surface insights, and accelerate value creation across portfolios; SaaS - Software as a Service, a cloud platform delivering unmatched performance, intelligence, and execution at scale; and S&C - Solutions and Consulting Suite, modular technology playbooks designed to manage, grow, and optimize company performance. With over a decade of experience supporting high-growth companies and private equity-backed platforms, brings deep domain expertise and a proven ability to turn technology into a strategic advantage. The Role We are looking for an experienced and passionate React Team Lead to lead the development of modern, scalable web applications. You will guide a team of React developers, enforce best practices in frontend architecture and design patterns, and ensure delivery of high-performance user interfaces. The ideal candidate has strong expertise in React (including Hooks and Context API), Redux, and frontend design patterns, and thrives in a fast-paced, collaborative environment. Key Responsibilities Lead, mentor, and support a team of React developers through code reviews, 1:1s, and hands-on coaching. Collaborate with product managers, designers, and backend engineers to define and prioritize features. Own and manage sprint planning, task estimation, and delivery timelines for the frontend team. Architect and implement complex user interfaces using React, Hooks, and Context API. Maintain and evolve a scalable state management solution using Redux Toolkit. Enforce modern frontend design patterns (such as container/presenter, compound components, render props, and HOCs). Build reusable component libraries and maintain design system alignment. Optimize application performance, accessibility, and cross-browser compatibility. Drive best practices in code quality, testing, CI/CD, and documentation. Maintain high unit and integration test coverage (e.g., using Jest, React Testing Library). Contribute to frontend architecture decisions and evaluate new tools/libraries as needed. Requirements 5+ years of experience in JavaScript/TypeScript with 3+ years in React.js Strong expertise with React Hooks, Context API, and Redux (Redux Toolkit preferred) Proven experience with frontend design patterns and clean code principles Experience integrating with RESTful APIs or GraphQL Solid understanding of HTML5, CSS3/SCSS, and responsive UI design Experience with component libraries and design systems (e.g., Storybook, Material UI, Tailwind) Familiarity with build tools like Webpack, Vite, and bundler optimizations Experience leading or mentoring engineers in a team setting Nice to Have Familiarity with performance profiling tools (e.g., Lighthouse, Chrome DevTools) Experience with SSR/SSG frameworks like Next.js Knowledge of accessibility standards (WCAG) Contributions to open-source frontend libraries What’s Offered Monthly compensation up to 8,000 USD Opportunity to lead a specialized frontend team in a fast-growing tech company Real influence on frontend architecture and design patterns

🏢 Summary: Full Stack Senior Java Developer role focused on designing and delivering scalable web applications using Java and React.js in an Agile environment. The position involves building high-performance front-end components, developing RESTful microservices, and managing cloud-based deployments with modern DevOps practices. This is a hybrid role with long-term cooperation on high-impact, international projects. 🗂️ Requirements: Bachelor’s or Master’s degree in Computer Science, Engineering or related field, 5+ years of experience as Full Stack Developer with Java and React.js, Commercial experience with Agile methodologies, Strong experience in RESTful API and microservices development, Hands-on experience with SQL and NoSQL databases, Experience with CI/CD pipelines and containerization tools, Knowledge of authentication and authorization mechanisms 📃 Skills: Java, Spring, SpringBoot, Hibernate, JPA, React, Redux, TypeScript, JavaScript, HTML5, CSS3, MaterialUI, Bootstrap, Tailwind, REST, Microservices, OAuth2, JWT, PostgreSQL, MySQL, MongoDB, Redis, Jenkins, GitHubActions, GitLab, AWS, Azure, GCP, Docker, Kubernetes 🏢 Description: Senior Java Developer IT · Warsaw (City Center) · Hybrid About the Client Our Client is a fast-growing, international technology company that provides innovative digital solutions for the global market. They are currently expanding and developing their R&D center in Warsaw. They focus on building high-quality, scalable products using modern tech stacks and agile methodologies. With a strong emphasis on engineering excellence, they offer a collaborative environment where experts can thrive and influence the technical direction of the products. Please note: Optiveum is a recruitment agency conducting this search on behalf of our Client. Role Overview We are seeking a highly skilled Full Stack Developer with expertise in Java and React.js to join our dynamic team. The ideal candidate should have over 5 years of experience in designing, developing, and deploying scalable web applications. This role requires strong front-end and back-end development expertise, working in an Agile environment to deliver high-quality software solutions. Key Responsibilities Front-End Development: Design and develop interactive, responsive, and high-performance UI components using React.js, Redux, and modern JavaScript (ES6+). Ensure cross-browser compatibility and a seamless user experience, while optimizing front-end performance and implementing best practices in UI/UX design. Back-End Development: Develop and maintain RESTful APIs and microservices using Java (Spring Boot, Hibernate, JPA). Implement robust authentication, authorization, and data management solutions, working with relational and NoSQL databases such as PostgreSQL, MySQL, and MongoDB. System Integration & Deployment: Integrate third-party services, APIs, and cloud-based solutions. Manage deployments using CI/CD pipelines and containerization tools like Docker & Kubernetes. Code Quality & Testing: Write clean, maintainable, and efficient code following best practices. Implement unit and integration tests for both front-end and back-end components. Collaboration & Agile Development: Work closely with UI/UX designers, product managers, and DevOps engineers. Participate in Agile/Scrum ceremonies and contribute to continuous process improvements. Requirements & Qualifications Experience & Education: Bachelor's or Master's degree in Computer Science, Engineering, or a related field. 5+ years of professional experience as a Full Stack Developer with Java & React.js, alongside experience working with Agile development methodologies. Front-End Stack: Proficiency in React.js, Redux, TypeScript, HTML5, CSS3, and modern JavaScript (ES6+). Strong understanding of state management libraries and component-based architecture. Experience with UI frameworks like Material-UI, Bootstrap, or Tailwind CSS. Back-End Stack: Expertise in Java, Spring Boot, Hibernate, JPA, and RESTful API development. Experience with microservices architecture and API Gateway implementations. Knowledge of authentication mechanisms like OAuth2, JWT, and session-based authentication. Database & DevOps: Experience with SQL databases (PostgreSQL, MySQL) and NoSQL databases (MongoDB, Redis). Hands-on experience with CI/CD tools (Jenkins, GitHub Actions, GitLab CI/CD). Familiarity with cloud platforms (AWS, Azure, GCP) and containerization using Docker, Kubernetes. Soft Skills: Strong problem-solving and analytical skills. Excellent communication and teamwork abilities. Ability to manage multiple priorities in a fast-paced environment. Passion for learning new technologies and improving existing processes. What Is Offered Compensation: Monthly compensation up to $6,200 (depending on experience and interview results). Contract Type: B2B contract via Optiveum. Work Model: Hybrid (3 days working from the office located in the center of Warsaw, 2 days working from home). Stability: Long-term cooperation with a stable, international organization. Growth: Opportunity to work with the latest technologies and high-impact projects.

🏢 Summary: Full Stack Development Lead role focused on delivering end-to-end solutions using React and C# .NET Core in a cloud-driven, microservices-based environment. The position combines hands-on development with architectural input and technical leadership in a fully remote B2B setup. The role involves close collaboration with cross-functional teams and contribution to modern DevOps and data workflows. 🗂️ Requirements: Proven full-stack experience with React, TypeScript, C# .NET Core, Strong knowledge of microservices architecture, Understanding of distributed systems, Experience with CI/CD pipelines, Experience with cloud platforms (Azure preferred), Experience with containers, Familiarity with DevOps practices, Ability to design APIs and event-driven components 📃 Skills: React, TypeScript, C#, .NET, Microservices, CI/CD, Azure, Docker, DevOps, PySpark, PowerBI, APIs 🏢 Description: Start Date: ASAP / Within 1 Month / Flexible Work Model: 100% remote Contract Type: B2B (160-180 PLN/h + VAT) We are looking for an experienced Full Stack Development Lead who will take ownership of end‑to‑end solutions across React and C# .NET Core while contributing to technical direction and supporting a collaborative engineering culture. This role is ideal for a strong Senior Full Stack Developer who is ready to expand into leadership responsibilities, work closely with cross‑functional teams, and influence architectural decisions in a modern, cloud‑driven environment. Expectations Proven experience in full‑stack development using React, TypeScript, and C# .NET Core. Good understanding of microservices , distributed systems, and CI/CD pipelines. Exposure to cloud platforms (Azure preferred), containers, and modern DevOps practices. Experience with data workflows (pyspark) or BI solutions (Power BI) is a strong advantage. Ability to collaborate with technical and business stakeholders and take initiative in solution design. Responsibilities Contribute to the design and delivery of full‑stack applications using React and C# .NET Core. Support architectural discussions around microservices, APIs, and event‑driven components. Collaborate with data engineers on pyspark workflows and Power BI reporting enhancements. Promote engineering best practices, code quality, and maintainable development patterns. Mentor team members and support planning, collaboration, and continuous improvement efforts. What We Offer Medicover healthcare package Multisport card Access to an e-learning platform Group life insurance

🏢 Summary: Hybrid Fullstack Developer role focused on building and maintaining scalable web applications using Java and React.js. The position involves designing backend services and RESTful APIs, developing modern frontend interfaces, and contributing to CI/CD and DevOps practices. Work includes testing, performance optimization, and collaboration on architecture and microservices. 🗂️ Requirements: Strong experience with Java and Spring Boot, Solid experience with React.js and state management, Experience designing and consuming RESTful APIs, Experience with microservices architecture, Proficiency in JavaScript, HTML5, CSS3, Experience with relational or NoSQL databases, Knowledge of unit and integration testing practices, Experience with CI/CD pipelines, Familiarity with Git and version control workflows, Ability to work with Agile/Scrum methodologies 📃 Skills: Java, Spring, SpringBoot, React, Redux, JavaScript, HTML5, CSS3, Webpack, Babel, ESLint, JUnit, Mockito, Jest, MySQL, PostgreSQL, NoSQL, Git, CI/CD, Docker, Kubernetes, AWS, Azure, GCP, Kafka, GraphQL, WebSocket 🏢 Description: We are looking for a highly skilled Fullstack Developer with expertise in Java and React.js to join our Kraków-based development team. You will design, develop, and maintain scalable, high-performance web applications, contributing to both backend services and rich frontend interfaces. This role follows a hybrid working model , with 2–3 days per week onsite in Kraków. Key Responsibilities Backend Development: Architect, implement, and maintain backend services using Java , Spring Boot , and related frameworks Frontend Development: Build responsive, modular, and maintainable React.js applications with a focus on component-driven design Design and implement RESTful APIs and microservices , ensuring high performance, security, and scalability Collaborate with cross-functional teams to define technical requirements , system architecture, and feature implementation Apply unit testing, integration testing, and end-to-end testing best practices (JUnit, Mockito, Jest, React Testing Library) Participate in code reviews , enforce coding standards, and promote best practices in clean code, SOLID principles, and design patterns Troubleshoot and optimize application performance and resolve production issues Manage CI/CD pipelines , automate deployments, and support DevOps practices Stay up-to-date with emerging technologies and frameworks to continuously improve application architecture Required Skills and Experience Strong experience with Java , Spring Boot , and related backend frameworks Solid experience with React.js , Redux , or state management libraries Proven experience in designing and consuming RESTful APIs and microservices architecture Proficient in JavaScript, HTML5, CSS3, and modern frontend tooling (Webpack, Babel, ESLint) Experience with relational databases (MySQL, PostgreSQL) and/or NoSQL databases Familiarity with Git , version control workflows, and Agile/Scrum methodologies Understanding of unit testing, integration testing, and test-driven development (TDD) Good problem-solving and communication skills in English Nice to Have Experience with TypeScript and advanced React patterns (Hooks, Context API, Suspense) Knowledge of Docker , Kubernetes , or cloud platforms (AWS, Azure, GCP) Experience with event-driven architectures , message queues , or Kafka Familiarity with GraphQL or WebSocket-based real-time applications

🏢 Summary: Mid-level Full-stack Developer role focused on building and maintaining web and mobile applications using React and .NET technologies. The position involves developing scalable backend services, microservices, and SEO-friendly frontends integrated with CMS, within a multinational Agile environment. The role combines frontend, backend, cloud, and DevOps responsibilities with regular team collaboration. 🗂️ Requirements: 2–4 years experience as FullStack Developer, .NET 8/10 proficiency, C# proficiency, Strong React knowledge, JavaScript proficiency, TypeScript proficiency, HTML5 knowledge, CSS3 knowledge, Experience with RESTful APIs, Experience with Git, Experience with Microsoft Azure (Functions, Durable Functions, CosmosDB, ServiceBus, Application Insights), Experience with CI/CD pipelines, Experience with Agile methodologies, Communicative English (B2+) 📃 Skills: .NET, C#, React, JavaScript, TypeScript, HTML5, CSS3, REST, Git, Azure, Functions, CosmosDB, ServiceBus, ApplicationInsights, CI/CD, ReactNative, Expo, Sanity, GROQ, Redux, RxJS, Tanstack, Sentry, Firebase, Analytics 🏢 Description: Join Our Team as a Full-stack Developer (React, C#)! We are seeking a talented Mid FullStack Developer proficient in .NET and React to join our team. As part of our company culture, we value collaboration and regular in-person interactions. Our team meets every two months in our Poznań office for informal gatherings to connect, share ideas, and strengthen teamwork in a relaxed setting. You will work in multinational environment and will be responsible for designing and implementing software solutions, utilizing both front-end and back-end technologies. This role requires strong problem-solving skills, excellent communication abilities, and a passion for delivering high-quality code. Ready to take the next step in your career? Apply now and join us! Key Responsibilities: • Design and develop SEO-friendly web application, based on React and TypeScript and integrated with Sanity CMS. • Contributing to a mobile application using React Native, TypeScript and Expo . • Build and maintain microservices to enhance the web experience, including features like roadside assistance, car repair bookings, and membership management. • Develop robust and scalable backend systems using .NET 8/10, Azure ServiceBus, Functions, CosmosDB and more. • Utilize Sentry for error monitoring and Google Analytics/Firebase to track user behaviour and optimize performance. Requirements : Proven experience (2-4 years) as a FullStack Developer Proficiency in .NET (preferably .NET 8/10), C# Strong understanding of front-end technologies, including React, JavaScript, TypeScript, HTML5, and CSS3 Practical knowledge of clean-code principles and patterns, drive to write clean, testable and maintainable code Experience with RESTful APIs and Web Services Knowledge of version control systems, such as Git Excellent problem-solving and analytical skills Familiarity with Microsoft Azure platform (Functions and Durable Functions, CosmosDb, ServiceBus, Application Insights) Experience with DevOps approach and CI/CD pipelines Strong communication and interpersonal skills, communicative English (B2+) Experience with Agile development methodologies Nice to have: Experience in working with Sanity CMS and GROQ query language (or any other headless CMS) Familiarity with Figma or similar tools At least basic knowledge about Server Side Rendering and libraries like: Redux, RxJS, Tanstack Experience in working with mobile apps and practical knowledge of React Native, Expo, Expo Application Services Knowledge of microservices architecture and software integration patterns We offer: Conference/workshop budget of approximately 10000 PLN!- the budget renews every year and can be used for conferences, workshops, training programs, certifications, studies, or other development initiatives. "Fabresikowe": one-time 1000 PLN bonus to create your work space more comfortable and more tailored to your needs! Relaxing office massages In-house trainings Team events Frequent company events Free breakfast every day Free beverages, fresh fruit, snacks Chill out room English and Norwegian classes

🏢 Summary: Senior Full Stack Developer role focused primarily on backend development with Python and FAST API, combined with React-based frontend work in a hybrid B2B model. The position involves designing scalable web applications, building high-performance APIs, and working with relational and NoSQL databases. Strong backend expertise is essential, with intermediate frontend skills and experience in modern DevOps practices. 🗂️ Requirements: 8+ years of professional software development experience, Expert proficiency in Python, Strong experience with FAST API, Strong knowledge of relational and NoSQL databases, Experience with SQLAlchemy ORM, Deep understanding of data structures and algorithms, Experience building RESTful APIs and microservices, Proficiency in writing unit and integration tests in Python, Strong knowledge of ReactJS and NodeJS, Experience with Redux or MobX, Familiarity with React Query, Experience with Material UI, CSS, and HTML, Experience with Jest and Cypress, Solid understanding of JavaScript and TypeScript 📃 Skills: Python, FASTAPI, SQLAlchemy, PostgreSQL, MySQL, MongoDB, DynamoDB, ReactJS, NodeJS, Redux, MobX, ReactQuery, MaterialUI, CSS, HTML, Jest, Cypress, JavaScript, TypeScript, Docker, Kubernetes, AWS, Azure, GCP, RabbitMQ, Kafka 🏢 Description: Working mode: Hybrid mode ( 2-3 days in a week from the office in Wroclaw or Warsaw) Experience Level: 8+ Years Contract Type: B2B About the Role We are looking for a highly skilled Senior Full Stack Developer with a primary focus on Python and FAST API to join the development team. The ideal candidate is a Python expert capable of architecting robust backend services. While React skills are required, we are flexible regarding the depth of frontend expertise (Intermediate level is acceptable), provided the backend strength is exceptional. Key Responsibilities Backend Architecture: Design, develop, and maintain scalable web applications using Python and FAST API . API Development: Build high-performance RESTful APIs and microservices, ensuring low latency and high availability. Database Management: Work with relational and NoSQL databases, utilizing ORMs like SQLAlchemy to design efficient database schemas and queries. Frontend Development: Develop and maintain user-facing features using ReactJS , ensuring the technical feasibility of UI/UX designs. Code Quality: Write clean, maintainable, and testable code; perform unit testing to ensure robustness. DevOps: Implement and manage CI/CD pipelines to streamline deployment processes. Collaboration: Work closely with cross-functional teams (Product, QA, and Design) in a hybrid working environment. Mandatory Technical Skills 1. Backend (Core Strength): Languages: Expert proficiency in Python . Frameworks: Strong experience with FAST API (Must-have). Experience with SQLAlchemy is highly preferred. Fundamentals: Deep understanding of data structures, algorithms, and space-time complexity. Database: Strong understanding of Relational (e.g., PostgreSQL, MySQL) and NoSQL (e.g., MongoDB, DynamoDB) databases. Testing: Proficiency in writing unit tests and integration tests for Python applications. 2. Frontend (Intermediate Level): Libraries: Strong knowledge of ReactJS and NodeJS . State Management: Experience with React workflows such as Redux or MobX . Tooling: Familiarity with React Query . Styling: Experience with Material UI , CSS , and HTML . Testing: Experience with frontend testing tools like Jest and Cypress . JavaScript: Solid understanding of JavaScript , TypeScript , and browser rendering behavior. Good to Have Experience with cloud platforms (AWS, Azure, or GCP). Knowledge of containerization (Docker, Kubernetes). Understanding of microservices architecture and message queues (RabbitMQ, Kafka).

🏢 Summary: Full-time hybrid Associate Frontend Team Lead role focused on leading a React development team, owning frontend architecture, and delivering high-performance web applications. The position combines hands-on coding with mentorship and technical leadership in building scalable, enterprise-grade AI-driven platforms. You will drive best practices in frontend design, state management, testing, and performance optimization. 🗂️ Requirements: 5+ years experience with JavaScript and TypeScript, Minimum 3 years experience with React.js, Strong proficiency in React Hooks and Context API, Experience with Redux and Redux Toolkit, Knowledge of frontend design patterns and clean code practices, Experience integrating REST or GraphQL APIs, Proficiency in HTML5, CSS3, SCSS, Experience with responsive UI development, Hands-on experience with component libraries and design systems, Familiarity with Webpack or Vite, Experience leading or mentoring developers, Experience with unit and integration testing 📃 Skills: JavaScript, TypeScript, React, ReactHooks, ContextAPI, Redux, ReduxToolkit, HTML5, CSS3, SCSS, REST, GraphQL, Webpack, Vite, Storybook, MaterialUI, Tailwind, Next.js, Jest, ReactTestingLibrary, Lighthouse, ChromeDevTools, WCAG, CICD 🏢 Description: 💰 Salary: 25,000-29,500 PLN/month 🌎 Hybrid from Warsaw, Poland 🕦 Full-time position, long-term ☑️ Contract of Employment We are looking for an Associate Frontend Team Lead to join our client, a technology company that builds AI-powered platforms and consulting solutions for enterprise operations, with a strong focus on the private capital sector. The company has over ten years of experience working with high-growth and PE-backed businesses, combining deep domain expertise with advanced technology to drive measurable results. In this role, the focus will be on leading a team of developers across front-end development, owning architectural decisions, and contributing directly to the codebase. You will mentor engineers and drive the delivery of high-performance web applications. Requirements: 5+ years of experience with JavaScript/TypeScript, including at least 3 years working with React.js Strong proficiency in React Hooks, Context API, and Redux (preferably Redux Toolkit) Demonstrated understanding of frontend design patterns and clean coding practices Experience integrating frontend applications with RESTful APIs or GraphQL services Solid knowledge of HTML5, CSS3/SCSS, and building responsive user interfaces Hands-on experience with component libraries and design systems (e.g., Storybook, Material UI, Tailwind) Familiarity with modern build tools such as Webpack and Vite, including optimization techniques Experience leading or mentoring developers within a team environment Nice to Have: Familiarity with performance analysis and profiling tools (e.g., Lighthouse, Chrome DevTools) Experience working with SSR/SSG frameworks like Next.js Understanding of web accessibility standards (WCAG) Contributions to open-source frontend projects or libraries Key Responsibilities: Guide and support a team of React developers through code reviews, one-on-one meetings, and practical coaching. Work closely with product managers, designers, and backend engineers to shape and prioritize features. Take ownership of sprint planning, task estimation, and meeting delivery deadlines for the frontend team. Design and build sophisticated user interfaces using React, including Hooks and the Context API. Develop and maintain a scalable state management approach using Redux Toolkit. Apply and promote modern frontend design patterns such as container/presenter, compound components, render props, and higher-order components. Create reusable components and ensure consistency with the overall design system. Improve application performance, accessibility, and compatibility across different browsers. Champion best practices for code quality, testing, CI/CD processes, and documentation. Ensure strong unit and integration test coverage using tools like Jest and React Testing Library. Participate in frontend architecture decisions and assess new tools and libraries when appropriate. Get to know DevsData: We are a technology consulting company and a recruitment agency, delivering software solutions to clients from Europe and the US. We work 100% remotely, in an international team, including people from Asia, London, or San Francisco. We employ people with experience in international corporations as well as students of the best technical and business universities.