Senior Backend Engineer (all genders)

ABOUT BABBEL LABS Babbel Labs is building the future of language learning. We are an AI-first, independent company within the Babbel group, based in Berlin. Our teams bring AI, research and product together to ship experiences that set a new standard for how people learn. THE ROLE Babbel Labs is rebuilding how learning content is created, stored and served, and how we decide what a learner sees next. The architecture for that is being set now, by a small number of engineers, and this role is one of them. You will build and run the services behind it, in a serverless-first TypeScript and Node stack on AWS, owning them from the contract at their edge to their behaviour under load. This is a senior individual-contributor role. You will design, build, ship and operate, and the seniority shows in the decisions you own rather than in a team reporting to you. HOW YOU'LL MAKE AN IMPACT - Build and evolve services across our learning platform, owning each one from its API contract through to what runs in production. - Take on services you did not write, alongside the people who did. - Design API and data contracts that hold up over time, with type-safe transforms between the API, the domain and persistence. - Run what you build. Instrument it, know how it fails, change live data safely, and be the person who works out why it broke. - Deliver with coding agents as a matter of course, and verify what they produce before you rely on it. YOUR SKILLS AND QUALIFICATIONS - Strong, hands-on backend engineering in TypeScript and Node as your primary working language today. We mean back-end services: not build tooling, and not the server a front-end framework happens to ship with. - Deep, practical AWS experience in a serverless-first setting. Lambda, API Gateway, DynamoDB and event streaming are our daily tools, and we want someone who has designed against them rather than only deployed onto them. - The ability to design API and data contracts and to model a domain, including type-safe transforms at the boundaries between the API, the domain and persistence. - Real production ownership. You have instrumented your own services, understood their failure modes, changed live data without losing any, and worked incidents on systems you owned. - Coding agents are part of your daily workflow, and you check their output before you rely on it. You are neither dismissive of them nor careless with them. - Self-sufficiency. You get yourself unstuck in an unfamiliar codebase without a minder, and you work within its grain rather than rewriting what you have not yet understood. - Working familiarity with infrastructure as code (Terraform) and CI/CD pipelines, enough to ship and change your own service's delivery. This is not an infrastructure role, so depth here is not the bar. - Python as a welcome secondary language. Some of our services are Python, and a Labs engineer can expect to touch them. NICE TO HAVE - Go or Rust for performance-critical components. Fully optional. - Experience with a monorepo build system and shared tooling. - Public technical work, such as open-source contributions or writing. WAYS OF WORKING This is a hands-on individual-contributor role on a small team that moves fast, agent-first, but with a structured and disciplined delivery approach. It is remote and Berlin-friendly. The interview process is deliberately short: an initial screen, followed by one working session with the hiring manager. Diversity at Babbel As part of our ongoing journey towards building a diverse, equitable and inclusive company, we welcome everyone to apply, especially those individuals who are underrepresented in tech. We are a learning company, inside and out, and we encourage you to apply even if you do not fit all the technical requirements - all candidates are assessed based on skills, qualifications and on our business needs. Please state your pronouns in your application, and let us know