Senior Product Engineer

About the Role This is a high-ownership product engineering role at a fast-growing, widely adopted open-source AI engineering platform — think the observability layer for the LLM era. The company is trusted by major enterprises and thousands of developers worldwide, with tens of millions of monthly SDK downloads. Product engineers here own the full lifecycle of a feature: from talking to users and writing the spec, through shipping the code, to writing the docs and the public changelog post. No handoffs — you see features through from user problem to production. Recent examples of features owned by a single engineer include a major agents release, a TypeScript SDK rewrite on OpenTelemetry, and a hosted MCP server for prompt management. That's the scope and ambition of this role. What You'll Do Own features end-to-end — user calls, spec writing, implementation, documentation, and public-facing changelog posts. No handoffs, full accountability. Work the full stack — React frontend, Next.js backend, ClickHouse analytics, and Python/TypeScript SDKs. You touch whatever the feature demands. Build in the open — write code that ships to the open-source community, respond to GitHub issues, review public PRs, and contribute to developer-facing documentation. Talk to users — participate in user interviews and translate feedback into product decisions and engineering solutions. Contribute to platform observability — work on tracing, monitoring, evaluation pipelines, prompt management, and cost/latency analytics. Maintain and distribute SDKs — help evolve and maintain client libraries used by a large developer community. What We're Looking For Must-haves (dealbreakers): 5+ years of professional software engineering experience building production-grade systems Located in the EU with the legal right to work in the EU — visa sponsorship is not available Able to travel to Berlin and be on-site approximately one week per month Required skills & experience: Ability to work EU timezones with regular overlap with CET business hours Hands-on experience building production-grade LLM applications or infrastructure (e.g. prompt management, evaluations, LLM tracing/observability) Experience contributing to and maintaining open-source projects in community-visible codebases (public GitHub repos) Practical experience with containerization and deployment workflows (Docker) and distributing/maintaining SDKs or client libraries Experience with instrumentation and observability: collecting and analyzing metrics such as latency and cost, and building tracing/monitoring tools Proven track record of shipping end-to-end product features and working cross-functionally with product managers and designers Strong written and async communication skills for public-facing code reviews, documentation, and community interactions Nice to have: Familiarity with data/analytics systems and columnar OLAP databases (e.g. ClickHouse) or similar scalable analytics stores Background at companies operating in AI/ML tooling, developer infrastructure, or observability (e.g. Arize AI, Weights & Biases, Braintrust, Comet, or similar) Compensation & Benefits Salary: €90,000 – €160,000 per year, depending on experience Equity participation in a well-funded, high-growth company Small, high-trust team with significant individual impact and ownership Location & Work Arrangement Remote-first across the EU — team members are distributed across Germany, Switzerland, the UK, the Netherlands, Spain, Sweden, Poland, Austria, and France On-site in Berlin, Germany approximately one week per month (travel required and reimbursed) Core collaboration hours in CET business hours Visa sponsorship is not available — EU work authorization required Find Jobs in Germany on Arbeitnow