Senior Fullstack Engineer - Custom Solutions

About Staffbase We inspire people to achieve great things together. Our mission is to help organizations unlock the power of inspirational communication with the first AI-native Employee Experience Platform . Our industry-leading and award-winning agentic AI communications channels - intranet, employee app and email solutions - create engaging experiences that connect and empower employees. Headquartered in Chemnitz, Germany and New York City, with offices in Berlin, London, Sydney, Tokyo, Prague, and Minneapolis–St. Paul, our diverse team of 550+ employees supports 1,500+ customers—reaching over 14 million employees—in transforming their employee experience. We are proud to be a Unicorn company—privately valued at over $1 billion—demonstrating strong growth, innovation, and lasting impact in our industry. Together, we’re shaping the future of workplace communication. We’re looking for an experienced Senior Fullstack Engineer to join a newly formed team at Staffbase that builds custom solutions — extending the functionality and capabilities of our award-winning employee communications platform to meet real customer needs. You’ll own solutions from beginning to end: shaping use cases together with stakeholders, building them across the stack, and validating them with the people who use them. You’ll also help bring structure to a growing team of mid-level engineers and mentor them along the way. We’re looking for empathetic, motivated team players who are driven by ownership and growth. Let’s talk! As part of our tech stack, we use: React.js, TypeScript, JavaScript, Node.js, Kotlin, Go, Java, MongoDB, REST APIs & SDKs, Docker, Terraform, Selenium and Cypress, to name a few. Our environment Working with skilled and like-minded professionals in a team that values diversity and inclusivity We aim to create a flexible and agile work environment that promotes the well-being and work-life balance of our employees We believe that team events during working hours play a vital role in building an exceptionally effective team, and we encourage them We are enthusiastic about technology and committed to using it to improve the world We follow the “You build it, you run it” approach and take pride in it The team You’ll join a newly formed team dedicated to building custom solutions that extend the Staffbase platform for our enterprise customers. We turn specific customer needs into reliable, scalable extensions — widgets, plugins, and integrations — that make our product work exactly the way each customer needs it to. Because the team is new, there’s real room to shape how we work: to set engineering standards, bring structure to our processes, and grow together. That’s where you come in. What you’ll be doing Own the development of custom solutions end-to-end — from technical design through implementation, testing, and release Partner with stakeholders (customers, consultants, and internal teams) to define and detail use cases before development, then validate solutions and gather feedback afterward Build across the stack: customer-facing UI in React and TypeScript, backend services, and integrations with Staffbase and third-party APIs Mentor mid-level engineers and help bring structure, engineering standards, and good practices to a newly formed team Work in a cross-functional, agile setup and produce high-quality, well-tested code Give and receive valuable feedback in our code review process, and continuously learn and share knowledge with your peers Work iteratively — pushing code frequently, keeping a healthy CI/CD pipeline, and automating where it helps What you need to be successful Solid professional experience (typically 5+ years) as a fullstack developer, including working within engineering teams and owning solutions from concept to delivery Strong frontend skills with React.js, TypeScript, and JavaScript, paired with solid backend experience (e.g. Kotlin, Java, or Node.js) Confidence working with REST APIs and SDKs, and integrati…