Senior JavaScript Engineer

Salary range: B2B - 40-43 E/h + VAT 💰 Ciklum is looking for a Senior JavaScript Engineer to join our team full-time in Poland.We are a custom product engineering company that supports both multinational organizations and scaling startups to solve their most complex business challenges. With a global team of over 4,000 highly skilled developers, consultants, analysts and product owners, we engineer technology that redefines industries and shapes the way people live. About the role: As a Senior JavaScript Engineer, become a part of a cross-functional development team engineering experiences of tomorrow. You will join a high-impact Design Systems team alongside other Senior Engineers to own high-impact workstreams and cross-functional partnerships. Our goal is to provide a seamless experience for millions of users on a global consumer review platform through robust, documented, and accessible UI patterns. You will operate with high autonomy, turning initial product needs into reusable components that enable product teams to move faster and more consistently. Responsibilities: • Feature Ownership: Take end-to-end ownership of complex system features such as Data Visualization suites, theme engines, or complex search/filtering patterns • System Architecture: Build for flexibility and reusability, ensuring features solve problems for multiple product teams without creating maintenance bottlenecks • UX Collaboration: Work in close partnership with UX designers to bridge the gap between Figma and code, ensuring technical feasibility during design reviews • Product Integration: Act as the dedicated technical point of contact for product areas to identify patterns that should be integrated into the core library • Accessibility Standards: Own the accessibility (A11y) for your features, ensuring components meet WCAG 2.1/2.2 standards • Release Management: Manage the lifecycle of features within a versioned code library, ensuring safe releases and clear migration paths • Technical Documentation: Produce clear, comprehensive documentation so that stakeholders, engineers, and AI agents can understand and extend your work • Mentorship: Participate in code reviews and RFCs, providing constructive feedback to help other engineers grow while maintaining a high quality bar Requirements: • Core Expertise: Advanced, hands-on proficiency with React, TypeScript, and CSS • Frontend Experience: 5+ years of professional experience in frontend web development • Systems Thinking: Proven experience building scalable libraries, shared infrastructure, or modular UI components • Inclusivity: Strong understanding of building accessible interfaces and applying WCAG standards • Strategic Execution: Ability to take vague requests, break them down into manageable tracks, and deliver at a steady, predictable pace • Communication: Upper-intermediate or higher level of spoken and written English Desirable:  • Design Systems: Proven experience contributing to a professional Design System or a major open-source project • Modern Tooling: Experience with Next.js, CSS Modules, SASS, or Styled Components • Testing: Familiarity with end-to-end testing frameworks like Playwright • Infrastructure: Understanding of AWS cloud infrastructure or CI/CD practices • Backend: Exposure to Node.js, MongoDB Personal skills: • Accountability: You take ownership and follow through on your responsibilities • Drive: You're proactive and results-oriented, always seeking better ways to solve problems • Self-development: You stay curious, seek feedback, and aim for continuous improvement • Effective communication: You communicate your ideas clearly and collaborate effectively in a team • Mentoring: You're open to helping less experienced team members and sharing knowledge What`s in it for you? • Strong community: Work alongside top professionals in a friendly, open-door environment • Growth focus: Take on large-scale projects with a global impact and expand your expertise • Tailored learning: Boost your skills with internal events (meetups, conferences, workshops), Udemy access, language courses, and company-paid certifications • Endless opportunities: Explore diverse domains through internal mobility, finding the best fit to gain hands-on experience with cutting-edge technologies • Flexibility: Enjoy flexibility – full remote working possibilities • Care: We’ve got you covered with company-paid medical insurance, mental health support, and financial & legal consultations About us: At Ciklum, we are always exploring innovations, empowering each other to achieve more, and engineering solutions that matter. With us, you’ll work with cutting-edge technologies, contribute to impactful projects, and be part of a One Team culture that values collaboration and progress. With delivery centers in Wrocław and Gdańsk, our 300+ professionals in Poland drive forward-thinking solutions for global clients. Join a community where collaboration sparks innovation—and your impact reaches millions. Want to learn more about us? Follow us on Instagram, Facebook, LinkedIn. Explore, empower, engineer with Ciklum! Interested already? We would love to get to know you! Submit your application. We can’t wait to see you at Ciklum.