Senior Software Engineer - JavaScript Fullstack (m/w/d)

Our newer frontends run on React.js, Next.js and TypeScript, wired to our platform through GraphQL and Apollo Client, on top of a polyglot ecosystem of Java and Go services built on Kafka. Some older apps still run on JavaScript, Redux and webpack, and you'll work in those too. Whether your background is frontend or fullstack, we care most about mindset. With AI in your toolkit, you are ready to work on anything: you'll follow a problem wherever it lives in the stack and solve it in the right place. We expect our engineers to use LLM and agentic tools (specs, agent loops, and agentic workflows) to iterate fast and build systems. Ship with AI: Use LLM and agentic tools as your default way of working to move fast, while keeping total ownership and full understanding of the generated code.

Build the Frontend: Create fast, accessible, and scalable web applications with React.js, Next.js, and TypeScript.

Go Beyond the Frontend: Extend backend services and GraphQL APIs when an experiment needs it, with Apollo Client managing data on the client.

Instrument features with clean tracking that respects each user's consent choices, so every test produces data the team can trust.

Translate the Hard Stuff: Work closely with product managers, UX designers, data analysts, and fellow engineers to turn complex scheduling requirements into clean, elegant solutions.

The Growth Experience: Proven, hands on experience with growth topics and product experimentation, such as A/B testing, funnel optimization, and activation or conversion work.

LLM and agentic tools are part of how you work every day, and you use them to deliver across the whole stack.

A Bachelor's in Computer Science, a related technical field, or equal practical experience.

Professional experience with JavaScript, TypeScript, React.js, and Next.js, and comfort working in older JavaScript and Redux code.

The Data Layer: Experience building production ready applications with client side data fetching via GraphQL (Apollo).

Frontend or fullstack, you are curious beyond your primary area, and you can read, debug, and change code across the stack.

We cannot sponsor visas or support relocation at this time.

The Backend Edge: Professional experience building backend services, ideally in Java, and designing GraphQL APIs.

The Data Craft: Comfort with experimentation platforms and feature flags such as GrowthBook, tracking plans such as Avo, product analytics, and the statistics behind a sound test.

The Craft: Experience with frontend performance optimization, responsive design, and modern browser APIs.

We deal with "Time" problems most companies never meet, from distributed, event driven services to the UX built on top of them. At this time, we are unable to sponsor a visa for this position or support with relocation.