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Agent guide: [/agents.md](https://www.wearedevelopers.com/agents.md). --- # Senior Frontend Developer | Haarlem, NL - **Company:** Sensys Gatso Group - **Location:** Haarlem, Netherlands - **Experience:** Expert - **Contract:** Permanent contract - **Skills:** JavaScript (Programming Language), Human-Computer Interaction, Interaction Design, Technical Data Management Systems, TypeScript, Eslint, ReactJS, Backend, Gitlab, Front End Software Development, React Redux, Cucumber (Software), Grpc, Docker - **Published:** July 18, 2026 - **Apply:** https://nl.indeed.com/viewjob?jk=37d9f83b1113fbfd ## About the Role * Engineering Expertise: 5+ years of experience developing complex interfaces for controlling real-time, device-facing and high-precision equipment. You are comfortable working both as a solo lead and as a collaborator. * Interaction & UX design: A genuine affinity for interaction design and the user experience of an interface You care how it feels to use, not only whether it renders. * Technical Mastery: You are an expert in React, TypeScript,gRPC, GitLab, and Docker. Your toolkit includes deep experience with Redux, ESlint, Jest, and Cucumber-style. * Architectural Mindset: A strong technical background that allows you to rapidly build user-friendly interfaces while maintaining a clean, scalable codebase. * Communication: Fluent in English with the ability to synthesize complex technical data into clear documentation. The Mindset & Spirit: * Adaptive Ownership: You thrive in a fluid environment. You are proactive, structured, and patient, capable of managing multiple international client requirements simultaneously. * Customer-Centric Innovation: You act as a front-line advocate, energized by creating tangible value and representing our mission with pride. * Technical Curiosity: You have a natural drive to explore latest technologies and an ability to expose backend features in an efficient, intuitive way. The "Extra Mile" (Bonus Points): * Native or near-native Dutch proficiency. * Experience in traffic safety, type approvals, or technical certifications. ## Description We are looking for a high-caliber Senior Frontend Developer to join our international team in Haarlem and take a leading role in our React-based operator interface. This is a mission-critical position for a developer who thrives on ownership. "You'll join an established team today and grow into the in-house center of gravity for the frontend work. If you want real ownership of a mature, safety-critical product - not a greenfield toy - this is it.", As our Senior Frontend expert, you will serve as the sole frontend authority in our Haarlem office. While you will be based locally, your impact extends globally: you will lead and collaborate closely with our contractor teams in eastern Europe to ensure seamless execution. You sit at the heart of the Engineering Department, acting as the vital link between our sophisticated hardware technology and our global clientele. Your mission is to translate ambitious traffic safety goals into precision-engineered interfaces that are correct, robust and genuinely usable - with a real feel for interaction design, not just implementation.. As the frontend specialist in a largely backend driven environment, you'll also be the person who carries the UI and UX perspective into engineering decisions and helps grow our in-house frontend capability. If you are motivated by high-stakes challenges and empowered autonomy, you'll find your home here., * UI Lead & Ownership: Take full end-to-end ownership of the user interface throughout the entire product lifecycle. * Navigate Complexity: Translate intricate customer needs and hardware capabilities into technically sound, user-friendly solutions. * Maintain & Evolve: Drive structural improvements to our current technical solutions, ensuring the frontend is future-proof. * Cross-Functional Synergy: Act as the bridge between customers, stakeholders, and local/remote backend developers to ensure seamless integration. * Radical Simplification: Distill complex technical concepts into intuitive designs, inspiring your peers, including backend engineers, to pursue simplicity in every solution. ## Related Videos - [The Pragmatic Architect: Balancing Necessity vs. Sufficiency in React Systems](https://www.wearedevelopers.com/videos/2101-the-pragmatic-architect-balancing-necessity-vs-sufficiency-in-react-systems) - [Boosting OpenSearch Performance: gRPC Search in Action](https://www.wearedevelopers.com/videos/1935-boosting-opensearch-performance-grpc-search-in-action) - [The two trees of React](https://www.wearedevelopers.com/videos/100180-the-two-trees-of-react) - [WeAreDevelopers LIVE - Modern DevOps for IoT Devices and More](https://www.wearedevelopers.com/videos/1805-wearedevelopers-live-modern-devops-for-iot-devices-and-more) - [Agile work at CARIAD – Creating a customer web application for controlling the vehicle ](https://www.wearedevelopers.com/videos/200-agile-work-at-cariad-creating-a-customer-web-application-for-controlling-the-vehicle) - [gRPC Load Balancing Deep Dive](https://www.wearedevelopers.com/videos/1576-grpc-load-balancing-deep-dive) ## Related Articles - [Software Developer Salary in The Netherlands [2023]](https://www.wearedevelopers.com/magazine/217-software-developer-salary-in-the-netherlands-2023) - [The Netherlands – Europe’s powerhouse for software development?](https://www.wearedevelopers.com/magazine/31-the-netherlands-europe-s-powerhouse-for-software-development) - [How to land a developer job in Amsterdam](https://www.wearedevelopers.com/magazine/36-how-to-land-a-developer-job-in-amsterdam) - [How to Find Tech Jobs in Amsterdam](https://www.wearedevelopers.com/magazine/279-how-to-find-tech-jobs-in-amsterdam) - [Best Companies in the Netherlands: Top 25 Companies in 2023 ](https://www.wearedevelopers.com/magazine/193-best-companies-in-the-netherlands-top-25-companies-in-2023) - [Dev Digest 133 - Back to Front](https://www.wearedevelopers.com/magazine/474-dev-digest-133-back-to-front)