Software Engineer (React)

🏢 Summary: Full-time Full Stack Software Engineer role focused on building AI-powered enterprise platforms using Java and React in a hybrid Warsaw setup. The position involves developing responsive front-end applications and scalable microservices-based back-end systems, integrating cloud services, and maintaining CI/CD pipelines. Long-term employment contract with emphasis on high-performance, secure, and maintainable solutions. 🗂️ Requirements: 5+ years experience as Full Stack Developer with Java and React.js, Strong proficiency in React.js and Redux, Strong knowledge of TypeScript, HTML5, CSS3, ES6+, Experience with state management and component-based architecture, Experience with UI libraries (Material-UI, Bootstrap, or Tailwind), Strong expertise in Java, Spring Boot, Hibernate, JPA, Experience building RESTful APIs and microservices, Knowledge of OAuth2, JWT, and session-based authentication, Experience with PostgreSQL or MySQL, Experience with MongoDB or Redis, Hands-on experience with CI/CD tools, Experience with AWS, Azure, or GCP, Experience with Docker and Kubernetes, Bachelor’s or Master’s degree in Computer Science or related field, Experience working in Agile environments 📃 Skills: Java, React, Redux, TypeScript, HTML5, CSS3, JavaScript, Spring, SpringBoot, Hibernate, JPA, REST, Microservices, OAuth2, JWT, PostgreSQL, MySQL, MongoDB, Redis, Jenkins, GitHub, GitLab, AWS, Azure, GCP, Docker, Kubernetes 🏢 Description: 💰 Salary: 21,000-22,000 PLN/month 🌎 Hybrid from Warsaw, Poland 🕦 Full-time position, long-term ☑️ Contract of Employment We are looking for a Software Engineer 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. Requirements: 5+ years of professional experience as a Full Stack Developer working with Java and React.js. Strong proficiency in React.js, Redux, TypeScript, HTML5, CSS3, and modern JavaScript (ES6+). In-depth understanding of state management solutions and component-based design principles. Experience working with UI libraries/frameworks such as Material-UI, Bootstrap, or Tailwind CSS. Solid expertise in Java, Spring Boot, Hibernate, JPA, and building RESTful APIs. Experience designing and working with microservices architecture and API Gateway patterns. Knowledge of authentication and authorization approaches, including OAuth2, JWT, and session-based methods. Experience with relational databases (PostgreSQL, MySQL) as well as NoSQL solutions (MongoDB, Redis). Hands-on experience using CI/CD tools like Jenkins, GitHub Actions, or GitLab CI/CD. Familiarity with cloud platforms such as AWS, Azure, or GCP, along with containerization tools like Docker and Kubernetes. Bachelor’s or Master’s degree in Computer Science, Engineering, or a related discipline. Experience operating within Agile development environments. Strong analytical thinking and problem-solving abilities. Key Responsibilities: Build and develop dynamic, responsive, and high-performing user interface components using React.js, Redux, and modern JavaScript (ES6+). Ensure applications function consistently across different browsers while delivering a smooth user experience. Enhance front-end performance and apply best practices in UI/UX design. Design, develop, and maintain RESTful APIs and microservices using Java technologies such as Spring Boot, Hibernate, and JPA. Implement secure authentication, authorization, and effective data management solutions. Work with both relational and NoSQL databases, including PostgreSQL, MySQL, and MongoDB. Integrate external services, APIs, and cloud-based platforms into applications. Oversee deployment processes using CI/CD pipelines and containerization technologies like Docker and Kubernetes. Produce clean, efficient, and maintainable code in line with established best practices. Develop and maintain unit and integration tests for both front-end and back-end systems. Collaborate closely with UI/UX designers, product managers, and DevOps specialists. Take part in Agile/Scrum processes and support ongoing improvements to development workflows.

🏢 Summary: Full-time Team Lead Software Engineer role focused on leading a full-stack team building high-performance web applications using React and Node.js. The position combines hands-on development with architectural ownership, mentoring, and delivery of scalable, AI-powered enterprise platforms. Work involves designing microservices, APIs, and cloud-based containerized deployments in a hybrid setup from Warsaw. 🗂️ Requirements: 7+ years full-stack experience with React.js and Node.js in production, 2+ years in Team Lead or senior engineering leadership role, Strong knowledge of React ecosystem (Redux, Hooks, component architecture, performance optimization), Proficiency in HTML5, CSS3, JavaScript ES6+, Experience with build tools (Webpack, Vite, or Babel), Experience with Express.js and RESTful API design, Knowledge of OAuth, JWT, session-based authentication, Experience with PostgreSQL or MySQL, Experience with MongoDB or other NoSQL databases, Hands-on experience with Docker, Familiarity with AWS or other major cloud platform, Experience with Git and Agile/Scrum methodologies 📃 Skills: React, Redux, JavaScript, HTML5, CSS3, Node.js, Express, REST, GraphQL, OAuth, JWT, PostgreSQL, MySQL, MongoDB, Docker, Kubernetes, AWS, Git, Webpack, Vite, Babel, Agile, Scrum 🏢 Description: 💰 Salary: 29,500–33,200 PLN/month 🌎 Hybrid from Warsaw, Poland 🕦 Full-time position, long-term ☑️ Contract of Employment We are looking for a Team Lead Software Engineer 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 and back-end development, owning architectural decisions, and contributing directly to the codebase. You will mentor engineers and drive the delivery of high-performance web applications using React and Node.js. Requirements 7+ years of full-stack development experience with React.js and Node.js in production environments 2+ years in a team lead, tech lead, or senior engineering leadership role Strong command of the React ecosystem: Redux, React Hooks, component architecture, and performance optimization Solid HTML5, CSS3, and modern JavaScript (ES6+); experience with build tooling such as Webpack, Vite, or Babel Proficiency with Express.js and API design (RESTful; GraphQL is a plus) Working knowledge of auth patterns: OAuth, JWT, session-based authentication Hands-on experience with PostgreSQL or MySQL; familiarity with MongoDB or similar NoSQL databases Docker experience required; Kubernetes is a plus Familiarity with at least one major cloud platform (AWS preferred) Comfortable with Git workflows and Agile/Scrum delivery Responsibilities Lead and mentor a team of software engineers; run code reviews, set engineering standards, and hold the bar on quality Architect and build full-stack features using React.js (with Redux and Hooks) on the front end and Node.js / Express.js on the back end Design scalable microservices and RESTful (or GraphQL) APIs aligned with product requirements Own the testing strategy: define coverage expectations, enforce unit and integration testing, and integrate quality gates into CI/CD pipelines Manage containerized deployments via Docker; collaborate on infrastructure with cloud platforms (AWS, Azure, or GCP) Partner directly with Product and Design to translate requirements into production-grade, accessible interfaces Model and maintain SQL and NoSQL data schemas; own data interaction patterns across services Monitor production systems, triage incidents, and drive root-cause resolution Keep technical documentation accurate and up to date 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. We employ people with experience in international corporations as well as the ones from the best technical and business universities. Find out more: https://devsdata.com

🏢 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.

🏢 Summary: Senior Software Engineer role focused on building a real-time AI platform, owning features end-to-end across frontend, backend, and cloud infrastructure. The position involves developing full-stack solutions and contributing to technical architecture in a remote-first startup environment. 🗂️ Requirements: Strong experience with TypeScript, Strong experience with React, Hands-on experience with AWS, Experience with Docker, Experience with Linux, Experience with Git, Fluent English 📃 Skills: TypeScript, React, AWS, Docker, Linux, Git, Express, Tailwind, WebSockets, LangChain 🏢 Description: 💰 Salary: 25 000 – 28 000 PLN net/month (B2B) + 26 days paid annual leave + equity (ESOP) 📍 Location: Remote (Poland) + meetup in Poznań once per month Our client is an early-stage startup building a real-time AI platform that supports professionals during live conversations. The system processes interactions in real time and delivers contextual insights, knowledge, and guidance while conversations are happening. The founding team has strong experience in distributed systems, AI platforms, and enterprise SaaS and is currently expanding the engineering team to accelerate product development. Role The client is looking for a Senior Software Engineer who enjoys owning features end-to-end, from frontend interfaces to backend services and cloud infrastructure. You will work closely with the founding team on building a real-time AI-powered product , contributing to both product development and technical architecture. Responsibilities Build full-stack features using TypeScript Develop React-based user interfaces Design and maintain backend services and APIs Work with AWS cloud infrastructure Build and run Docker-based services Improve performance and reliability of real-time systems Requirements Strong experience with TypeScript and React Hands-on experience with AWS Experience with Docker and Linux Comfortable working with Git workflows Fluent English Experience working in remote teams Nice to Have Express Tailwind CSS Experience with real-time systems Knowledge of WebSockets / streaming Experience with LLM frameworks (e.g. LangChain) What the Client Offers Opportunity to build a product from an early stage Direct influence on architecture and product direction Work with experienced founders Remote-first environment Competitive salary + equity High level of ownership and autonomy

🏢 Summary: Offer for an experienced React FrontEnd Developer to design and build responsive, high-performance user interfaces in a hybrid model in Warsaw. The role focuses on developing modern web applications using React and related technologies, with strong emphasis on testing, accessibility, and performance optimization. The position involves close collaboration with cross-functional teams to deliver robust, user-centric digital products. 🗂️ Requirements: 6+ years of experience in JavaScript development, 6+ years of experience in TypeScript development, Commercial experience with React.js, Experience with Redux, Hands-on experience with HTML5, Hands-on experience with CSS3, Ability to write cross-browser compatible code, Understanding of object-oriented programming concepts and design patterns, Knowledge of functional programming paradigms, Understanding of asynchronous programming, Experience with TDD, Experience with continuous integration, Knowledge of Git and branch management, Experience with front-end debugging tools, Experience working in Agile methodology 📃 Skills: JavaScript, TypeScript, React, Redux, Next.js, HTML5, CSS3, Git, TDD, CI, OOP, FP 🏢 Description: React FrontEnd 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 are 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. With over a decade of experience supporting high-growth companies, they bring deep domain expertise and a proven ability to turn technology into a strategic advantage. Role Overview We are seeking a skilled React FrontEnd Developer to design and develop responsive user interfaces. In this role, you will collaborate with cross-functional teams to deliver robust, user-centric solutions while driving best practices in testing, accessibility, and performance optimization. Key Responsibilities UI Development: Designing and developing responsive user interfaces using React Testing & Integration: Implementing and maintaining TDD in applications and continuous integration. Driving best practices in testing, accessibility, and performance optimization. Collaboration: Collaborating with a cross-functional team of project managers, project analysts, and sales staff to deliver high-quality, interactive products on time. Collaborating cross-functionally with design, backend, QA, and product teams to deliver robust and user-centric solutions. Requirements & Qualifications Experience & Education: 6+ years of experience in JavaScript and TypeScript development. A Bachelor's degree in Computer Science or equivalent is preferred. Core Tech Stack: Must know a modern front-end JS framework, such as React.js + Redux; Next.js is a bonus. Hands-on experience with HTML5, CSS3. Proficiency in writing cross-browser compatible code. Programming Paradigms: Should understand OO concepts and design patterns, and their application to JavaScript development. Knows functional programming paradigms. Understands asynchronous programming paradigms and best practices. Tools & Debugging: Git and branch management knowledge. Experience debugging front-end problems and a knowledge of front-end debugging tools. Familiarity with custom package creation and integration. Soft Skills & Methodology: Experience with Agile methodologies and development practices. Good communication skills and good organization skills. Ability to work under pressure and deliver against tight deadlines. What Is Offered Compensation: Monthly compensation up to $4,800 USD . 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.

🏢 Summary: Full-time Senior Full Stack Developer role focused on building scalable, data-driven platforms for financial and enterprise sectors using Node.js and React. The position involves designing microservices, developing RESTful APIs, and creating responsive front-end applications in a hybrid work model (Warsaw). 🗂️ Requirements: 5+ years experience as Senior Full Stack Developer, Strong expertise in Node.js, Strong expertise in React, Experience with Express.js, Experience building RESTful or GraphQL APIs, Knowledge of OAuth and JWT authentication, Proficiency in Redux, HTML5, CSS3, ES6+, Experience with Vite, Webpack or Babel, Experience with MySQL or PostgreSQL, Experience with AWS, Azure or GCP, Experience with Docker and Kubernetes, Proficiency with Git 📃 Skills: Node.js, React, Express.js, GraphQL, REST, OAuth, JWT, Redux, HTML5, CSS3, JavaScript, ES6, Vite, Webpack, Babel, MySQL, PostgreSQL, AWS, Azure, GCP, Docker, Kubernetes, Git, SQL, MongoDB, CI/CD 🏢 Description: Senior Full Stack Developer (Node.js + React) 💰 Salary: 23,000-24,800 PLN/Month 💻 Warsaw, Poland (Hybrid - 3 days in office, 2 days remote) 🕦 Full-time ☑️ B2B or CoE We’re looking for a Senior Full-Stack Developer to join a fast-growing international tech company focused on building modern, data-driven platforms that power digital transformation in the financial and enterprise sectors. Requirements: 5+ years of experience as a Senior Full Stack Developer with significant expertise in Node.js and React. Strong experience in building server-side applications using Node.js and Express.js. Hands-on experience with API development and integration, particularly with GraphQL or RESTful services. Strong knowledge of authentication and authorization mechanisms (OAuth, JWT, session-based). Front-end proficiency in React.js, Redux, HTML5, CSS3, and modern JavaScript (ES6+). Familiarity with front-end build tools such as Vite, Webpack, and Babel. Strong experience with databases such as MySQL and  PostgreSQL. Experience with cloud platforms (AWS, Azure, or GCP), as well as containerization and orchestration tools such as Docker and Kubernetes. Strong experience using Git and version control systems. Proficiency in English (both written and spoken). Key Responsibilities: Design, build, and maintain scalable, high-performance server-side applications and RESTful APIs using Node.js and Express.js. Develop and maintain interactive, responsive user interfaces using React.js, Redux, and modern JavaScript (ES6+). Lead the design and implementation of scalable architectures and microservices. Work closely with database engineers to design efficient schemas and manage data interactions using SQL databases or MongoDB. Ensure reliable deployments and smooth release of updates using CI/CD pipelines and Docker. Write unit and integration tests and optimize performance to ensure high-quality code. Collaborate closely with cross-functional teams to define and implement technical solutions. Improve system performance, reliability, and long-term maintainability through optimization and best practices. 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. Find out more: https://devsdata.com/

🏢 Summary: Full-time, 100% remote Senior Frontend Developer role focused on building and scaling complex, responsive web applications powered by AI-driven platforms. The position involves architecting high-quality front-end solutions, integrating with back-end services, and ensuring performance, scalability, and cross-browser compatibility. The role also includes driving best practices, code quality, and modern front-end standards within the team. 🗂️ Requirements: Strong knowledge of HTML5, CSS3, JavaScript (ES6), Strong understanding of DOM, Experience with React.js, Experience with Material UI, Experience with Responsive Design and cross-browser compatibility, Familiarity with SASS or LESS, Understanding of BEM methodology, Knowledge of CSS-in-JS, Knowledge of browser storage (cookies, localStorage, sessionStorage), Proficiency with npm or yarn, Experience with Jest or equivalent testing frameworks, Understanding of SEO best practices, Familiarity with TypeScript, Knowledge of SSR and service workers, Experience with Webpack, Vite, or Rollup, Understanding of browser extensions integration 📃 Skills: HTML5, CSS3, JavaScript, ES6, DOM, React, MaterialUI, SASS, LESS, BEM, CSS-in-JS, cookies, localStorage, sessionStorage, npm, yarn, Jest, TypeScript, SSR, Webpack, Vite, Rollup, SEO, ServiceWorkers 🏢 Description: Senior Frontend Developer (100% remote) 💰 Salary: 20,000-23,000 PLN/month 🌎 100% Remote 🕦 Full-time position ☑️ B2B or Contract of Employment We are looking for a Senior Frontend Developer for a partner client that helps businesses use artificial intelligence to run more efficiently and grow faster. The company builds and provides digital platforms and consulting services that enable organizations to manage operations, analyze data, and improve performance. Their solutions combine AI, automation, and deep business expertise to help clients simplify workflows, gain insights, and deliver greater value. Requirements: HTML5 , CSS3 , JavaScript (ES6) Strong understanding of the Document Object Model (DOM) Skilled in Responsive Design and cross-browser compatibility Experience with React.js and Material UI Familiarity with CSS preprocessors such as SASS or LESS Understanding of BEM methodology and CSS-in-JS approaches Knowledge of browser storage mechanisms (cookies, localStorage, sessionStorage) Proficient in using package managers (npm/yarn) Experience in unit testing using Jest or equivalent frameworks Understanding of SEO best practices Familiarity with TypeScript for type-safe, large-scale applications Knowledge of server-side rendering (SSR) and service workers Experience with code bundling and modern module bundlers (e.g., Webpack, Vite, Rollup) Understanding of browser extensions and their integration with web applications Responsibilities: Develop and maintain  complex, responsive user interfaces for large-scale web applications. Architect and integrate front-end components with back-end APIs and services , ensuring security, scalability, and performance. Drive the implementation of pixel-perfect UI/UX designs across browsers and devices. Provide technical mentorship to junior developers and guide the team in adopting modern best practices. Conduct code reviews , enforce standards, and maintain a clean, modular codebase. Evaluate and recommend new frameworks, tools, and libraries to enhance productivity. Manage project timelines, estimate development efforts, and collaborate effectively with cross-functional teams. Maintain comprehensive front-end documentation , design patterns, and style guides. Stay updated with industry trends , emerging technologies, and front-end innovations to continuously improve team capabilities. Participate in architectural discussions , ensuring long-term scalability and maintainability of the front-end ecosystem. 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. Find out more: https://devsdata.com

🏢 Summary: Full-time Senior Back-End Engineer (Node.js) role focused on designing and maintaining scalable, high-performance server-side applications and APIs for modern, data-driven platforms. The position involves building RESTful services, integrating with third-party systems, ensuring code quality through testing, and optimizing system reliability and performance. Hybrid work model in Warsaw with B2B or CoE contract options. 🗂️ Requirements: Strong experience with Node.js, Strong experience with Express.js, Experience building and integrating APIs (GraphQL or REST), Knowledge of OAuth, JWT, and session-based authentication, Experience with MySQL, Experience with PostgreSQL, Experience writing unit tests with Chai and Mocha, Experience using Git and version control systems 📃 Skills: Node.js, Express.js, GraphQL, REST, OAuth, JWT, MySQL, PostgreSQL, Chai, Mocha, Git 🏢 Description: Senior Back-End Engineer (Node.js) 💰 Salary: 18,700-20,900 PLN/Month 💻 Warsaw, Poland (Hybrid - 3 days in office, 2 days remote) 🕦 Full-time ☑️ B2B or CoE We’re looking for a Senior Back-End Engineer to join a fast-growing international tech company focused on building modern, data-driven platforms that power digital transformation in the financial and enterprise sectors. Requirements: Strong experience in building server-side applications using Node.js and Express.js. Hands-on experience with API development and integration, particularly with GraphQL or RESTful services. Strong knowledge of authentication and authorization mechanisms (OAuth, JWT, session-based). Strong experience with databases such as MySQL and  PostgreSQL. Experience writing unit tests with tools such as Chai and Mocha. Strong experience using Git and version control systems. Proficiency in English (both written and spoken). Nice To have: Bachelor’s degree in Computer Science or a related field. Experience with cloud platforms (AWS, Azure, or GCP), as well as containerization and orchestration tools such as Docker and Kubernetes. Experience with microservices architecture. Experience setting up CI for static analysis and test execution. Experience developing RAG applications and storing data in vector embeddings. Key Responsibilities: Design, build, and maintain scalable, high-performance server-side applications and RESTful APIs using Node.js and Express.js. Guide and supervise the development of key code components to ensure long-term reliability and scalability. Integrate with front-end components and third-party services. Actively review the codebase, recommending and implementing refinements where needed. Write unit and integration tests and optimize performance to ensure high-quality code. Collaborate closely with cross-functional teams to define and implement technical solutions. Improve system performance, reliability, and long-term maintainability through optimization and best practices. 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. Find out more: https://devsdata.com/

🏢 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: Software Engineer role in a long-term international project, working in a cross-functional team responsible for full product lifecycle from design to production support. The position involves backend and frontend development using modern technologies in an iterative delivery model. Hybrid work model with 5 days per month in the office. 🗂️ Requirements: Minimum 5 years of commercial software development experience, Experience with at least one programming language: Kotlin, Python, or JavaScript, Willingness to work across backend and frontend technologies, Working knowledge of Unix/Linux environments, Understanding of databases: MongoDB, Redis, PostgreSQL, Experience with HTTP APIs and RESTful services, Ability to provide production support and troubleshoot performance and security issues, Good English communication skills 📃 Skills: Kotlin, Python, JavaScript, Unix, Linux, MongoDB, Redis, PostgreSQL, REST, HTTP, .NET, C# 🏢 Description: Software Engineer (Kotlin / Python / JavaScript) Location: Kraków or Warsaw (hybrid — 5 days per month in the office) Contract type: B2B — 130–140 PLN/h Project: Long-term international project About the Role We are looking for a Software Engineer to join a collaborative product team working in an iterative delivery model. The team is responsible for the full lifecycle of the product — from design and development to production support — following the principle: “you build it, you support it.” This role offers an opportunity to work with modern technologies across backend and frontend, while continuously learning new programming languages and tools. Key Responsibilities Work in a cross-functional team of 4–6 engineers Break down requirements into user stories and deliver iteratively to production Design technical solutions aligned with architectural guidelines Provide production support, including troubleshooting bugs, performance, and security issues Identify and manage technical debt alongside new feature development Collaborate closely with team members, including pair programming Ensure high quality and maintainability of delivered solutions Requirements Minimum 5 years of relevant commercial experience Experience with at least one programming language (Kotlin, Python, or JavaScript preferred) Willingness to learn multiple technologies across backend and frontend Working knowledge of Unix/Linux environments Understanding of databases from a usage perspective (MongoDB, Redis, PostgreSQL) Experience with HTTP APIs (RESTful services) Good English communication skills (team communication in English) Nice to Have Knowledge of .NET / C# What We Offer Hybrid work model — only 5 days per month from the office (Kraków or Warsaw) Private medical care (Medicover) Sports card (Multisport or equivalent) Life insurance Long-term, stable cooperation Opportunity to work with modern technologies in an international environment Support for professional development and learning