Senior Software Engineer (SDK)

<h3>About the Role</h3><p style="min-height:1.5em">This is a rare opportunity to own the SDK layer of a widely adopted open-source AI engineering platform — the kind of tooling that sits at the very first touchpoint developers have with the product. The SDKs you build ship to <strong>millions of downloads per month</strong>, running in production environments ranging from serverless functions to long-running agent loops. When you ship, thousands of developers benefit the same day.</p><p style="min-height:1.5em">The bar is high: zero-failure reliability, minimal CPU and memory overhead, and idiomatic developer experience across Python and TypeScript. You'll be the person who sets that bar and upholds it.</p><h3>What You'll Do</h3><ul style="min-height:1.5em"><li><p style="min-height:1.5em"><strong>Own Python and TypeScript SDKs end-to-end</strong> — reliability, performance, and developer experience. You'll drive major version rewrites and architectural improvements, including work on OpenTelemetry-based tracing.</p></li><li><p style="min-height:1.5em"><strong>Design APIs developers love</strong> — every detail of naming, parameter structure, breaking change communication, and documentation is yours to shape.</p></li><li><p style="min-height:1.5em"><strong>Integrate with the AI ecosystem</strong> — build and maintain integrations with LLM frameworks, model providers, and agent runtimes; keep pace with a fast-moving ecosystem.</p></li><li><p style="min-height:1.5em"><strong>Maintain and grow open-source community health</strong> — triage GitHub issues, review pull requests, engage with contributors, and communicate clearly on public channels.</p></li><li><p style="min-height:1.5em"><strong>Drive performance</strong> — profile, benchmark, and optimize SDK footprint across latency, memory, and throughput dimensions.</p></li><li><p style="min-height:1.5em"><strong>Own the release lifecycle</strong> — versioning strategy, changelog communication, compatibility testing, and CI/CD automation for library releases.</p></li><li><p style="min-height:1.5em"><strong>Collaborate cross-functionally</strong> — work closely with product and data teams across EU timezones in a small, high-trust distributed team.</p></li></ul><h3>What We're Looking For</h3><p style="min-height:1.5em"><strong>Required:</strong></p><ul style="min-height:1.5em"><li><p style="min-height:1.5em">5+ years of professional software engineering experience, with at least 2 years building or maintaining SDKs or client libraries</p></li><li><p style="min-height:1.5em">Proven track record designing, implementing, and maintaining production-grade SDKs — including API design, versioning, packaging, and release management</p></li><li><p style="min-height:1.5em">Experience optimizing library/SDK performance (profiling, reducing latency and memory usage, improving throughput)</p></li><li><p style="min-height:1.5em">Hands-on experience with observability, tracing, metrics, or monitoring systems — designing or instrumenting telemetry for debugging and analytics</p></li><li><p style="min-height:1.5em">Proficiency in at least one SDK-relevant language (Python, TypeScript/JavaScript, Go, or Java) with ability to write idiomatic, production-quality code</p></li><li><p style="min-height:1.5em">Active open-source experience: handling GitHub issues, PR reviews, and community interactions</p></li><li><p style="min-height:1.5em">Strong written and verbal communication skills; comfortable writing documentation and engaging publicly (GitHub, social/developer channels)</p></li><li><p style="min-height:1.5em">Experience with automated testing and CI/CD pipelines for libraries (unit/integration testing, release automation, compatibility testing)</p></li><li><p style="min-height:1.5em">Ability to work effectively in small, distributed EU-timezone teams</p></li><li><p style="min-height:1.5em"><strong>Legal authorization to work in the EU — no visa sponsorship available</strong></p></li></ul><p style="min-height:1.5em"><strong>Nice to Have:</strong></p><ul style="min-height:1.5em"><li><p style="min-height:1.5em">Familiarity with analytics or large-scale telemetry systems (e.g., OLAP/columnar analytics databases)</p></li><li><p style="min-height:1.5em">Bachelor's degree in Computer Science, Engineering, or equivalent practical experience</p></li></ul><h3>Location</h3><p style="min-height:1.5em">This is a <strong>hybrid remote role</strong> based in Europe. You'll work remotely most of the time, with the expectation of being on-site in <strong>Berlin, Germany</strong> approximately one week per month. The team spans Germany, Austria, Switzerland, the Netherlands, France, Sweden, the UK, Spain, and Poland.</p><h3>Compensation &amp; Benefits</h3><ul style="min-height:1.5em"><li><p style="min-height:1.5em"><strong>Salary:</strong> $90,000 – $160,000 USD annually (or local equivalent), depending on experience and location</p></li><li><p style="min-height:1.5em">Opportunity to have meaningful impact on a high-adoption, widely used open-source project in the AI/ML space</p></li><li><p style="min-height:1.5em">Work within a small, senior engineering team backed by top-tier investors including Y Combinator</p></li></ul><p>Find more <a href="https://www.arbeitnow.com/english-speaking-jobs">English Speaking Jobs in Germany</a> on Arbeitnow</a>