Full Stack JavaScript Developer (Node.js / React)

🏢 Summary: Full Stack JavaScript Developer role focused on building and maintaining a large-scale data processing and analytics platform, covering backend services, frontend applications, and scalable data pipelines. The position involves developing RESTful APIs, microservices, and cloud-based solutions in AWS, with strong emphasis on performance, security, and database optimization. The role includes working on complex systems using Node.js, React, and PostgreSQL in a modern engineering environment. 🗂️ Requirements: Strong experience with Node.js (v22+), Strong experience with Express.js, Solid knowledge of React (v16+), Experience with PostgreSQL and query optimization, Very good understanding of asynchronous JavaScript, Experience designing RESTful APIs, Knowledge of microservices architecture, Understanding of distributed systems, Experience with testing frameworks, Experience with Git, Knowledge of modern build tools, Understanding of web security best practices, Basic knowledge of AWS, Ability to implement authentication and authorization mechanisms (JWT, ACL) 📃 Skills: JavaScript, Node.js, Express.js, React, PostgreSQL, SQL, REST, Microservices, AWS, JWT, ACL, Jest, Mocha, Git, Webpack, Rollup, ETL, CI/CD, Docker 🏢 Description: Full Stack JavaScript Developer (Node.js / React) About CRIF CRIF is an international company providing credit and business information services, data processing, and advanced decisioning solutions. We support financial institutions, insurers, utilities, and enterprises with reliable data, analytics, and secure, scalable technology platforms. WBO (White Blue Ocean) is CRIF’s personal and cyber security division focused on advanced monitoring of the Open and Dark Web. Using AI and machine learning, it identifies leaked, stolen, or exposed data and delivers proactive alerts for individuals and companies. Role Overview We are looking for an experienced Full Stack JavaScript Developer to join the WBO team and help build a complex data processing and analytics platform, covering backend services, frontend applications, and large-scale data pipelines. Key Responsibilities Design, develop, and maintain scalable backend services using Node.js Build modern, responsive web applications with React Develop and maintain RESTful APIs and microservices Implement and optimize data processing pipelines (ETL, streaming) Design and optimize PostgreSQL databases and complex queries Implement authentication and authorization mechanisms (JWT, ACL) Optimize application performance and data processing efficiency Write and maintain unit and integration tests Participate in code reviews and ensure high code quality Deploy and maintain applications in an AWS cloud environment Troubleshoot production issues and implement sustainable solutions Collaborate with the team on architecture and technical decisions Document technical solutions and API specifications Required Skills & Experience Strong experience with Node.js (v22+) and Express.js Solid knowledge of React (v16+) Experience with PostgreSQL and query optimization Very good understanding of asynchronous JavaScript (async/await, Promises) Experience designing scalable RESTful APIs Knowledge of microservices and distributed systems Familiarity with testing frameworks (Jest, Mocha) Experience working with Git and modern build tools (Webpack / Rollup) Understanding of web security best practices Basic knowledge of AWS and cloud architecture concepts Nice to Have Experience with AWS Lambda, S3, Athena, CloudWatch Docker and CI/CD pipelines (e.g. Jenkins) TypeScript, Redis, Bull, Socket.io Python or Rust for performance-critical components Experience working with and modernizing legacy systems What We Offer Employment contract Hybrid work model (50/50 – office in Kraków ) Work on large-scale, data-driven systems in an international environment Real impact on system architecture and technology decisions Modern tech stack and strong engineering culture Cooperation with experienced and supportive teams Competitive salary aligned with your experience (salary range will be shared during the first interview)

🏢 Summary: Full Stack Developer role focused on building scalable backend services in Java and modern, responsive front-end applications in React.js. The position involves designing RESTful APIs, collaborating with cross-functional teams, and delivering clean, maintainable, high-quality code in a hybrid work model. 🗂️ Requirements: Commercial experience with Java, Experience with Spring Boot framework, Strong knowledge of React.js, Proficiency in modern JavaScript, Experience designing and consuming RESTful APIs, Experience with relational or non-relational databases, Experience with version-controlled collaborative development, Availability to work onsite in hybrid model (Cracow) 📃 Skills: Java, SpringBoot, React, JavaScript, REST, SQL, NoSQL, AWS, Azure, GCP, Docker, Kubernetes, CICD 🏢 Description: 𝗪𝗲 𝗔𝗿𝗲 𝗛𝗶𝗿𝗶𝗻𝗴: 𝗝𝗮𝘃𝗮 𝗮𝗻𝗱 𝗥𝗲𝗮𝗰𝘁.𝗷𝘀 𝗙𝘂𝗹𝗹 𝗦𝘁𝗮𝗰𝗸 𝗗𝗲𝘃𝗲𝗹𝗼𝗽𝗲𝗿 We are currently seeking a skilled and motivated Full Stack Developer with strong expertise in Java and React.js to join our growing team. In this role, you will be responsible for designing and developing scalable backend services using Java, as well as building modern, responsive user interfaces using React.js. You will work closely with cross-functional teams to deliver high-quality, reliable solutions, while ensuring that your code is clean, maintainable, and efficient. 𝗞𝗲𝘆 𝗥𝗲𝘀𝗽𝗼𝗻𝘀𝗶𝗯𝗶𝗹𝗶𝘁𝗶𝗲𝘀: Developing robust backend applications using Java, ideally with Spring Boot Creating intuitive and high-performing front-end applications using React.js and modern JavaScript Designing and consuming RESTful application programming interfaces Collaborating with colleagues across engineering, product, and design teams Contributing to code reviews and continuous improvement practices 𝗪𝗲 𝗮𝗿𝗲 𝗹𝗼𝗼𝗸𝗶𝗻𝗴 𝗳𝗼𝗿 𝗰𝗮𝗻𝗱𝗶𝗱𝗮𝘁𝗲𝘀 𝘄𝗵𝗼 𝗵𝗮𝘃𝗲: Proven experience working with Java and related frameworks Strong knowledge of React.js and modern JavaScript standards Experience working with relational or non-relational databases A proactive approach to problem-solving and a strong attention to detail Excellent communication and teamwork skills It would be beneficial if you also have: Experience working with cloud platforms such as Amazon Web Services, Microsoft Azure, or Google Cloud Platform Exposure to continuous integration and continuous delivery pipelines Familiarity with containerisation technologies such as Docker and Kubernetes 📍 𝗟𝗼𝗰𝗮𝘁𝗶𝗼𝗻: Cracow, Poland (Hybrid – 3 days per week onsite) 💼 𝗘𝗺𝗽𝗹𝗼𝘆𝗺𝗲𝗻𝘁 𝗧𝘆𝗽𝗲: B2B If you are passionate about building impactful technology and are looking to take the next step in your career, we would be delighted to hear from you. Please apply or get in touch directly for more information.

🏢 Summary: Long-term opportunity for a Middle/Senior Full Stack Developer to design, develop, and optimize a live educational platform using Node.js and React.js. The role covers both frontend and backend development, system architecture, integrations, and DevOps within a mature product continuously enhanced for performance and security. 🗂️ Requirements: 4+ years of professional software development experience, 4+ years of hands-on JavaScript frontend development, Strong knowledge of React.js, Strong knowledge of Node.js, Strong knowledge of NestJS, Experience with PHP, Experience with AWS, Experience with Docker, Experience with MySQL, Confident use of Git 📃 Skills: JavaScript, React.js, Node.js, NestJS, PHP, AWS, Docker, MySQL, Git, Salesforce, Contentful, Kubernetes, GraphQL, Jenkins, CI/CD 🏢 Description: Project overview The project is live and has been actively developed for over 5 years, with continuous feature enhancements and security improvements. All development is carried out on our side. Our client is a US‑based nonprofit organization developing an educational platform that supports students in learning computer science and building coding projects. The platform provides curriculum materials, teaching tools, progress tracking, collaboration features, and portfolio‑building capabilities. The mission of the platform is to help close the gender gap in the tech industry. Position overview We are looking for a Strong Middle/Senior Full Stack Developer (Node.js + React.js) to join our dynamic team. You will be involved in the design, development, and optimization of both frontend and backend functionality, working closely with a cross‑functional team on a long‑term product. Responsibilities Develop and maintain platform features using Node.js, React.js, and NestJS Participate in system design, architecture discussions, and technical decision‑making Improve platform performance, scalability, and security Implement integrations with third‑party systems (e.g., Salesforce, Contentful) Work closely with product managers, designers, and QA to deliver high‑quality features Write clean, maintainable, and well‑tested code Participate in code reviews and provide constructive feedback to the team Contribute to DevOps processes using AWS, Docker, and CI/CD tools Troubleshoot, debug, and resolve technical issues in both frontend and backend components Support continuous enhancement and modernization of the long‑running project Requirements 4+ years of professional software development experience 4+ years of hands‑on experience with JavaScript for frontend development Strong knowledge of: React.js, Node.js, NestJS Experience with PHP Experience working with AWS and Docker Experience with MySQL Confident use of Git Nice to have Solid understanding of Kubernetes Experience with GraphQL Familiarity with Jenkins and CI/CD automation Experience integrating with Salesforce and Contentful What We Offer: Vacation days : Up to 26 business days per year. 10 illness/special days off per year (fully paid, no medical papers needed) for all contract types Health and life insurance (Luxmed) MyBenefit platform with Multisport option Internal psychological support service English language classes from the first working day Access to external learning platforms : O’Reilly, LinkedIn Learning, Udemy, and a wide catalog of diverse internal training Flexible workplace : work from the office, from home, or choose a hybrid option Tech Skills Mentoring Program Opportunities to develop as a public speaker, mentor, or technical interviewer Fully paid idle (bench) when not involved in a project Certification reimbursement (AWS, GCP, Microsoft, etc.)

🏢 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 Developer role focused on building high-performance, data-driven web applications with a strong emphasis on React and complex graph visualizations. The position involves developing scalable Node.js APIs and transforming large-scale graph data into interactive UI components. Fully remote B2B contract within a Poland-based team working standard business hours. 🗂️ Requirements: 7+ years of software development experience, Expert knowledge of React and TypeScript, Strong experience with Node.js and TypeScript for server-side development, Experience building REST and GraphQL APIs, Extensive experience with Redux state management, Proficiency with Storybook for component-driven development, Ability to optimize frontend performance for large-scale datasets, High proficiency in English (B2/C1) 📃 Skills: React, TypeScript, Node.js, Redux, GraphQL, REST, D3.js, GoJS, Cytoscape, Neo4j, Cypher, AGGrid, Storybook, Microservices 🏢 Description: Senior Full Stack Developer (React / Node.js ) The Role As a Full Stack Developer with a strong emphasis on React , you will be responsible for crafting the visual and interactive elements of applications that visualize complex financial and ownership networks. While the backend is built on Node.js , your primary challenge will be turning intricate graph data into seamless, high-performance UI components. Key Responsibilities React Excellence: Lead the development of complex, data-driven web applications using React and TypeScript . Graph Visualization: Transform raw graph data into interactive, responsive UIs using D3.js, GoJS , or similar libraries. Backend Services: Develop and maintain scalable APIs and microservices using Node.js and TypeScript . Data Integration: Work closely with graph engineers to integrate real-time GraphQL data and high-end AG Grid reports. Performance: Optimize the frontend to handle and render large-scale, nested datasets without lag. Architecture: Maintain reusable components in Storybook and ensure a consistent, scalable codebase. Technical Requirements (Must Have) 7+ years of experience in software development. Expert React & TypeScript: Deep knowledge of modern React patterns and performance tuning. Node.js & TypeScript: Solid experience in building server-side applications and REST/GraphQL APIs. State Management: Extensive experience with Redux . Modern Tooling: Proficiency with Storybook for component-driven development. English: High proficiency ( B2/C1 ) for daily collaboration with US and Netherlands-based stakeholders. Nice to Have Data Viz: Experience with D3.js, GoJS , or Cytoscape . Graph Databases: Familiarity with Neo4j, or Cypher Reporting: Advanced knowledge of AG Grid . Assignment Details Contract Type: B2B Work Model: 100% Remote / Work from Home Business Hours: 9:00 – 17:00 (Warsaw Time) Location: Poland-based delivery team

🏢 Summary: Long-term opportunity for a Strong Middle/Senior Full Stack Developer (Node.js + React.js) to design, develop, and optimize a live educational platform. The role involves full-stack feature development, system design participation, third-party integrations, and performance, scalability, and security improvements. You will work on a mature product with continuous enhancements using modern cloud and DevOps practices. 🗂️ Requirements: 4+ years professional software development experience, 4+ years frontend experience with JavaScript, Strong knowledge of React.js, Strong knowledge of Node.js, Strong knowledge of NestJS, Experience with PHP, Experience with AWS, Experience with Docker, Experience with MySQL, Proficient with Git 📃 Skills: JavaScript, React, Node.js, NestJS, PHP, AWS, Docker, MySQL, Git, CI/CD, Salesforce, Contentful, Kubernetes, GraphQL, Jenkins 🏢 Description: Client Our client is a US‑based nonprofit organization developing an educational platform that supports students in learning computer science and building coding projects. The platform provides curriculum materials, teaching tools, progress tracking, collaboration features, and portfolio‑building capabilities. The mission of the platform is to help close the gender gap in the tech industry. Project overview The project is live and has been actively developed for over 5 years, with continuous feature enhancements and security improvements. All development is carried out on our side. Position overview We are looking for a Strong Middle/Senior Full Stack Developer (Node.js + React.js) to join our dynamic team. You will be involved in the design, development, and optimization of both frontend and backend functionality, working closely with a cross‑functional team on a long‑term product. Responsibilities Develop and maintain platform features using Node.js, React.js, and NestJS Participate in system design, architecture discussions, and technical decision‑making Improve platform performance, scalability, and security Implement integrations with third‑party systems (e.g., Salesforce, Contentful) Work closely with product managers, designers, and QA to deliver high‑quality features Write clean, maintainable, and well‑tested code Participate in code reviews and provide constructive feedback to the team Contribute to DevOps processes using AWS, Docker, and CI/CD tools Troubleshoot, debug, and resolve technical issues in both frontend and backend components Support continuous enhancement and modernization of the long‑running project Requirements 4+ years of professional software development experience 4+ years of hands‑on experience with JavaScript for frontend development Strong knowledge of: React.js, Node.js, NestJS Experience with PHP Experience working with AWS and Docker Experience with MySQL Confident use of Git Nice to have Solid understanding of Kubernetes Experience with GraphQL Familiarity with Jenkins and CI/CD automation Experience integrating with Salesforce and Contentful

🏢 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: Full Stack Developer role with a primary focus on backend development in Java, responsible for building and maintaining scalable, secure microservices and REST APIs within an Agile environment. The position involves database design, cloud integration, and CI/CD pipeline participation, with additional work on modern React-based frontend components. The role emphasizes high code quality, performance optimization, and secure application architecture. 🗂️ Requirements: 5+ years experience in Full Stack or Backend development, Strong proficiency in Java, Experience with Spring Boot, Hibernate, JPA, Experience building REST APIs and microservices, Knowledge of OAuth2 and JWT authentication, Experience with SQL and NoSQL databases, Experience with CI/CD pipelines, Experience with Docker and Kubernetes, Cloud platform experience (AWS, Azure, or GCP), Experience working in Agile teams, Bachelor’s or Master’s degree in Computer Science or related field 📃 Skills: Java, Spring, SpringBoot, Hibernate, JPA, REST, Microservices, OAuth2, JWT, PostgreSQL, MySQL, MongoDB, Redis, React, Redux, TypeScript, JavaScript, HTML5, CSS3, MaterialUI, Bootstrap, Tailwind, Jenkins, GitHubActions, GitLab, Docker, Kubernetes, AWS, Azure, GCP 🏢 Description: Overview We are a company leveraging AI to optimize business operations. Our mission is to provide digital solutions and consulting services that help companies grow and create value. By using modern technology, we simplify processes, increase efficiency, and discover new revenue opportunities—especially in private capital markets. Our ecosystem includes: PaaS (Platform as a Service): A core platform that enhances workflows, provides actionable insights, and supports value creation. SaaS (Software as a Service): A cloud platform offering robust performance and intelligent tools at scale. S&C (Solutions & Consulting): Flexible tools and methodologies to manage, grow, and improve company performance. With over 10 years of experience working with fast-growing companies and private equity businesses, we know how to harness technology to deliver tangible business advantages. Job Description We are looking for Full Stack Developer with strong Java expertise. While your main focus will be backend systems, experience with modern frontend technologies (React.js, TypeScript) is also required. You will join an Agile team to design, build, and maintain scalable, secure, and high-performing applications. Key Responsibilities Backend Development (Primary Focus) Develop and maintain REST APIs and microservices using Java (Spring Boot, Hibernate, JPA). Implement secure authentication, authorization, and data handling mechanisms. Design and optimize databases (PostgreSQL, MySQL, MongoDB) for performance and reliability. Integrate with third-party APIs, cloud services, and internal systems. Participate in deployment pipelines using CI/CD tools (Jenkins, GitHub Actions, GitLab CI/CD) and containerization (Docker, Kubernetes). Frontend Development (Nice-to-Have) Build responsive UI components using React.js, Redux, and modern JavaScript/TypeScript. Apply best practices in UI/UX design, performance optimization, and cross-browser compatibility. Work with UI frameworks like Material-UI, Bootstrap, or Tailwind CSS. Code Quality & Testing Write clean, maintainable, and well-documented code. Create unit and integration tests for backend services, and frontend components if applicable. Collaboration & Agile Development Collaborate with designers, product managers, and DevOps engineers. Participate in Agile/Scrum ceremonies and contribute to process improvement initiatives. Required Skills & Experience Backend Strong proficiency in Java , Spring Boot, Hibernate, JPA, and REST API development. Experience with microservices architecture and API Gateway. Knowledge of authentication/authorization protocols: OAuth2, JWT, sessions. Frontend (Optional / Nice-to-Have) Experience with React.js, Redux, TypeScript, HTML5, CSS3, and modern JavaScript. Understanding of state management and component-based design. Familiarity with UI libraries/frameworks: Material-UI, Bootstrap, or Tailwind CSS. Database & DevOps SQL (PostgreSQL, MySQL) and NoSQL (MongoDB, Redis). CI/CD pipelines (Jenkins, GitHub Actions, GitLab CI/CD). Cloud platform experience (AWS, Azure, GCP) and containerization (Docker/Kubernetes). Qualifications Bachelor’s or Master’s degree in Computer Science, Engineering, or related field. 5+ years of experience as a Full Stack or Backend Developer. Experience working in Agile teams. Strong problem-solving and analytical skills. Soft Skills Excellent communication and teamwork abilities. Ability to manage multiple tasks in a fast-paced environment. Eagerness to learn new technologies and improve processes.

🏢 Summary: Senior Full Stack Developer role focused on building and maintaining a complex web application for visualization of financial relationship networks using React, Node.js, GraphQL, and graph databases. The position involves end-to-end development, backend integration, graph data visualization, and architectural decision-making in a fully remote B2B setup. Candidates will work with scalable microservices, streaming systems, and advanced frontend performance optimization. 🗂️ Requirements: Minimum 7 years of commercial software development experience, Expert knowledge of React, Advanced TypeScript skills, Strong experience with Redux, Experience optimizing frontend performance for large datasets, Solid Node.js backend development experience, Experience building REST APIs, Experience building GraphQL APIs, Knowledge of application architecture and design patterns, Experience with Storybook, English level B2/C1, Ability to make technical decisions independently 📃 Skills: React, Node.js, TypeScript, Redux, GraphQL, REST, Storybook, MongoDB, Neo4j, Kafka, D3.js, GoJS, Cytoscape, AGGrid, Cypher, Gremlin, Neptune 🏢 Description: Senior Full Stack Developer (React / Node.js / Graph Data) Stawka: 190 – 200 PLN / godz. netto (+ VAT) Forma współpracy: Kontrakt B2B Model pracy: 100% Zdalnie (w ramach zespołu w Polsce) Godziny pracy: 9:00 – 17:00 (Warsaw Time) O projekcie Dołączasz do nowo powstającego, zespołu projektowego w Polsce, który przejmuje całkowitą odpowiedzialność za end-to-end rozwój zaawansowanej aplikacji webowej opartej na technologii baz grafowych. Przenosimy "serce" systemu do Polski. Aplikacja służy do wizualizacji złożonych sieci powiązań finansowych . Szukamy mocnego zawodnika – Seniora z krwi i kości, który bez problemu połączy skomplikowany świat danych backendowych z najwyższej klasy interfejsem użytkownika. Twój profil: Silny Full Stack (Mocny React + Solidny Node.js) W tej roli łączysz dwa światy. Z jednej strony potrzebujemy Twojej eksperckiej wiedzy w React , aby płynnie renderować ogromne ilości danych i sieci powiązań grafowych. Z drugiej strony Twój kod w Node.js będzie stanowił "serce" komunikacji między API GraphQL a rozbudowanym ekosystemem danych (Kafka, MongoDB, Neo4j). Twoje zadania: React Excellence: Projektowanie i rozwój zaawansowanych, wydajnych aplikacji webowych przy użyciu React i TypeScript. Wizualizacja Danych Grafowych: Transformacja surowych danych z bazy grafowej na interaktywne, responsywne komponenty UI (z użyciem D3.js, GoJS lub pokrewnych). Rozwój Core Backend: Projektowanie, utrzymanie i optymalizacja skalowalnych mikroserwisów w Node.js (TypeScript). Ewolucja GraphQL & Integracja: Projektowanie optymalnych schematów i wydajnych resolverów, które spajają frontend z bazami NoSQL/Neo4j oraz systemami streamingowymi (Kafka). Quality & Architecture Leadership: Aktywny udział w podejmowaniu decyzji architektonicznych, dbanie o czystość kodu (rygorystyczne Code Review) oraz rozwój reużywalnych komponentów w Storybook. Wymagania (Must Have) – Szukamy Eksperta: Minimum 7 lat komercyjnego doświadczenia w rozwoju oprogramowania. Expert React & TypeScript: Głęboka znajomość nowoczesnych wzorców React, zaawansowanego zarządzania stanem ( Redux ) oraz optymalizacji wydajności frontendowej przy renderowaniu dużych, zagnieżdżonych zestawów danych. Solidny Node.js & TypeScript: Praktyczne doświadczenie w budowaniu stabilnych, produkcyjnych systemów backendowych i wydajnych API (REST / GraphQL ). Architektura & Narzędzia: Bardzo dobra znajomość architektury aplikacji, wzorców projektowych oraz praca ze Storybook . Język angielski: Minimum B2/C1 – warunek konieczny do codziennej, płynnej współpracy z interesariuszami z USA i Holandii. Zdolność do brania odpowiedzialności: Szukamy osoby z samodzielnym podejściem, która potrafi podjąć decyzję techniczną i dba o stabilność całego systemu. Mile widziane (Mile widziane): Praktyczna znajomość baz NoSQL oraz baz grafowych (np. MongoDB, Neo4j , AWS Neptune) wraz z zapytaniami Cypher/Gremlin. Doświadczenie z systemami event-driven / streamingowymi (np. Apache Kafka ). Zaawansowana znajomość AG Grid pod kątem rozbudowanego raportowania. Doświadczenie z bibliotekami do wizualizacji danych (D3.js, GoJS, Cytoscape). Co oferujemy? Realny wpływ: Nie jesteś tylko wykonawcą zadań. Jako Senior masz decydujący głos w kwestiach architektonicznych i technologicznych. Unikalny Stack Technologiczny Stabilność i profesjonalizm plus praca zdalna Zainteresowany? Aplikuj

🏢 Summary: Full-Stack Developer role focused on building and delivering secure, scalable applications using React, Next.js, Node.js, and Azure. The position emphasizes shift-left testing, API development, and end-to-end ownership of high-quality, resilient solutions. You will work across the stack to design, develop, and optimize modern web applications and microservices. 🗂️ Requirements: 3+ years of full-stack development with TypeScript, Next.js, Node.js, React, Experience with RESTful and GraphQL APIs, Knowledge of Microsoft Azure, Familiarity with CI/CD pipelines, Understanding of DevOps practices, Knowledge of web security principles, Experience with Git, Understanding of software engineering principles and design patterns 📃 Skills: TypeScript, JavaScript, Next.js, React, Node.js, Azure, REST, GraphQL, CI/CD, Git, DevOps, Microservices, Testing, Security, APIs 🏢 Description: We are seeking a highly skilled Full-Stack (React/Node.js + Azure) Developer to join our team and play a pivotal role in implementing a new project. In this position, you will be instrumental in shaping our shift-left testing strategy, ensuring that quality and resilience are embedded from the very beginning of development. Leveraging your strong expertise in Next.js, you will work across the stack—from building modern, performant front-end experiences to designing and integrating APIs and microservices. You will take ownership of delivering secure, scalable, testable, and maintainable solutions that meet the highest engineering standards. Responsibilities Design, build, and maintain full-stack applications using TypeScript, Next.js, Node.js, and React Champion the shift-left approach by embedding quality early in the SDLC, writing unit, integration, and end-to-end tests alongside feature development Collaborate with product managers, designers, and other developers to deliver high-quality features and user experiences Develop and maintain RESTful and GraphQL APIs, ensuring robust integration with front-end and third-party services Optimize application performance, scalability, and security Participate in code reviews, providing constructive feedback and ensuring adherence to best practices Troubleshoot, debug, and resolve technical issues across the stack Contribute to continuous improvement of development processes, tools, and methodologies Document technical decisions, system architecture, and codebase for future reference and onboarding Requirements 3+ years of experience developing full-stack applications with TypeScript, Next.js, Node.js, and React Strong understanding of software engineering principles, design patterns, and best practices Familiarity with CI/CD pipelines and modern DevOps practices Knowledge of Microsoft Azure Proficiency in building and consuming RESTful and GraphQL APIs Solid understanding of web security principles and secure coding practices Experience with version control systems, preferably Git Excellent problem-solving skills and attention to detail Good work ethic and strong sense of ownership of end result Excellent verbal and written communication skills, B2 level of English We offer/Benefits We gather like-minded people: Engineering community of industry professionals Friendly team and enjoyable working environment Flexible schedule and opportunity to work remotely within Poland Chance to work abroad for up to 60 days annually Business-driven relocation opportunities We provide growth opportunities: Outstanding career roadmap Leadership development, career advising, soft skills, and well-being programs Certification (GCP, Azure, AWS) Unlimited access to LinkedIn Learning, Get Abstract, Cloud Guru English classes We cover it all: Stable income (Employment Contract or B2B) Participation in the Employee Stock Purchase Plan Benefits package (health insurance, multisport, shopping vouchers) Strategically located offices featuring entertainment and relaxation zones, table tennis and football, free snacks, fantastic coffee, and more Referral bonuses Corporate, social and well-being events Please, note: The set of bonuses might vary based on the role you apply for – specifics will be discussed with our recruiter during the general interview. We will reach out to selected candidates exclusively. EPAM is a leading global provider of digital platform engineering and development services. We are committed to having a positive impact on our customers, our employees, and our communities. We embrace a dynamic and inclusive culture. Here you will collaborate with multi-national teams, contribute to a myriad of innovative projects that deliver the most creative and cutting-edge solutions, and have an opportunity to continuously learn and grow. No matter where you are located, you will join a dedicated, creative, and diverse community that will help you discover your fullest potential.