Senior Software Engineer (Java+React)

🏢 Summary: Full-time hybrid Software Engineer role focused on building responsive, AI-driven web applications for enterprise platforms using modern JavaScript technologies. The position involves developing high-quality React-based interfaces, applying TDD and CI practices, and collaborating within cross-functional Agile teams. Long-term B2B contract based in Warsaw with competitive salary. 🗂️ Requirements: 6+ years experience with JavaScript, 6+ years experience with TypeScript, Strong knowledge of design patterns in JavaScript, Proficiency in React with Redux, Experience with Next.js, Understanding of functional programming concepts, Strong knowledge of asynchronous programming, Experience with Git and branch management, Experience debugging front-end applications, Experience creating and integrating custom packages, Understanding of object-oriented programming principles, Practical experience with HTML5, Practical experience with CSS3, Experience in Agile environments, Ability to develop cross-browser compatible code 📃 Skills: JavaScript, TypeScript, React, Redux, Next.js, HTML5, CSS3, Git, TDD, CI, Agile 🏢 Description: 💰 Salary: 14,500-17,000 PLN/month 🌎 Hybrid from Warsaw, Poland 🕦 Full-time position, long-term ☑️ B2B 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: 6+ years of experience working with JavaScript and TypeScript Solid understanding of design patterns and how to apply them in JavaScript development. Proficiency in a modern front-end JavaScript framework such as React.js with Redux; experience with Next.js is an advantage. Familiarity with functional programming concepts. Strong grasp of asynchronous programming and its best practices. Knowledge of Git and experience with branch management. Experience troubleshooting front-end issues and using relevant debugging tools. Familiarity with creating and integrating custom packages. Good understanding of object-oriented programming principles and their use in JavaScript. Ability to perform effectively under pressure and meet strict deadlines. Practical experience with HTML5 and CSS3. Experience working within Agile development environments and practices. Strong communication and organizational abilities. Skilled in developing cross-browser compatible code. A Bachelor’s degree in Computer Science or a related field is preferred. Key Responsibilities: Creating and building responsive user interfaces using React. Applying and maintaining test-driven development (TDD) practices along with continuous integration processes. Working closely with a cross-functional team that includes project managers, analysts, and sales representatives to deliver high-quality, interactive products within deadlines. Promoting and implementing best practices in testing, accessibility, and performance optimization. Partnering with design, backend, QA, and product teams to develop reliable, user-focused solutions.

🏢 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: 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: 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: 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: Mid-level Full-Stack Developer role focused on building and modernizing a cloud-based practice management and CRM platform. The position involves a 60/40 split between Angular frontend and Node.js/Nest.js backend, contributing to migration from monolith to microservices and upgrading to the latest Angular version. Fully remote (Poland-based) with strong impact on architecture and product quality. 🗂️ Requirements: 2–3 years of commercial experience in full-stack web development, Commercial experience or strong willingness to work with Angular, Experience with Node.js backend development, Practical knowledge of Nest.js, Basic knowledge of SQL, Experience or willingness to implement automated E2E tests, Polish residency, Working proficiency in Polish, Notice period of 1 month or less 📃 Skills: Angular, Node.js, Nest.js, SQL, Playwright, Microservices, Cloud, ORM, E2E 🏢 Description: Position: Full-Stack Developer Location: Remote (Poland-based) Salary: 14500 – 19500 PLN / month Our client is an innovative software company delivering a modern, cloud-based practice management and CRM solution dedicated to professional services. The platform streamlines day-to-day operations, including workload management and automated document generation. The development team is highly autonomous, focused on refactoring their core product from a monolith into scalable microservices, migrating to the newest technology stacks, and fostering an environment with strong developer ownership. We are looking for a mid-level Full-Stack Developer (approx. 2–3 years of commercial experience) to join a tight-knit Polish development team. In this role, you will work on both frontend and backend tasks (approx. 60% Front-End and 40% Back-End workload), having a real impact on technology choices and product quality. Requirements: Around 2–3 years of commercial experience in full-stack web development. Professional experience or strong openness to working with Angular (the project is currently on Angular 6 and undergoing a migration to the latest stable version). Solid knowledge of backend development using Node.js, preferably with Nest.js (used for all new microservices). Basic understanding of SQL (complex queries are supported by in-house ORM and AI tools, backed by thorough code reviews). Familiarity with or interest in testing practices (manual testing with beta users and expanding automated E2E tests using Playwright ). Polish residency and working proficiency in Polish (mandatory for active participation in daily sync meetings). Notice period of 1 month or less . Mindset focused on autonomy, taking ownership of tasks, and willingness to challenge the status quo. Responsibilities: Developing new features and maintaining the cloud-based platform (60% FE / 40% BE split). Actively participating in architecture modernization (refactoring the monolith into microservices and migrating the legacy frontend to the latest Angular version). Writing clean, maintainable code and participating in peer code reviews. Ensuring software quality through self-testing and implementing automated E2E test scenarios with Playwright. Onboarding smoothly into the codebase (handling smaller bug fixes and minor features in Month 1, progressing to designing and delivering a major complex feature by Month 3). Attending daily team synchronization meetings (at 10:00 AM Polish time). Offer: Salary: 14500 – 19500 PLN / month (depending on experience). Contract type: Long-term B2B Contract (open to both permanent-like cooperation and 12-month fixed contracts). Working model: 100% Fully Remote work. Flexible working hours (with core presence during the 10:00 AM daily sync). Hardware: Company-provided laptop and necessary equipment. No on-call duties or weekend shifts. Great culture: High levels of engineering autonomy, flat structure, and direct impact on the final product. Fast recruitment process: 3 stages (1h Live Coding data processing task $\rightarrow$ ~3h Homework assignment $\rightarrow$ 1h final CTO interview) with rapid feedback provided within 1–2 business days after each stage.

🏢 Summary: Long-term B2B opportunity for a senior engineer to deliver production-ready code and shape system architecture in a microservices environment. The role combines hands-on Java and React development with architectural responsibilities in a global, collaborative setup. It focuses on high-frequency delivery and technical excellence within the financial sector. 🗂️ Requirements: Strong Java experience (latest versions), Strong React experience, Experience with microservices architecture, Experience delivering RESTful APIs, Experience with PostgreSQL, Proven high-frequency code delivery, Experience in banking or financial sector 📃 Skills: Java, React, Microservices, REST, PostgreSQL, Banking, Docker, Kubernetes 🏢 Description: Working mode : Hybrid - 6 days per month at the Warsaw office Contract type : B2B, long term cooperation Rate : 200 PLN/h Summary: This role focuses on hands-on development and system architecture, driving engineering culture, and enhancing business growth through technical expertise in a collaborative, global environment. Main Responsibilities: Deliver code to production and support system architecture aligned to microservices Understand business, engineering, and non-functional requirements Drive the desired engineering culture across teams Collaborate with a globally diverse team across regions Proactively remove impediments, assess risks, and communicate issues to program management Identify and eliminate process inefficiencies Key Requirements: Strong Java and React programming experience Experience in microservice architecture Background in the financial sector, particularly banking Proven capability of delivering code changes at high frequency Experience with RESTful API delivery Familiarity with PostgreSQL databases Recent Java experience, preferably with the latest versions Experience with ReactJS for UI application development Nice to Have: Knowledge of containers and orchestration technologies like Docker and Kubernetes. Other Details: This position offers the opportunity to work within a multi-regional team on innovative projects. Ideal for candidates seeking to leverage their development skills in a dynamic and evolving business context.

🏢 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.