Senior Software Engineer (SDK)

<h3>About the Role</h3><p style="min-height:1.5em">This is a high-ownership engineering role at a fast-growing, open-source AI engineering platform — think of it as the Datadog for LLM observability. The platform is trusted by thousands of development teams worldwide, and the SDKs you'll own are downloaded <strong>millions of times each month</strong>, often serving as the very first touchpoint a developer has with the product.</p><p style="min-height:1.5em">The SDKs run in production environments ranging from serverless functions to long-running agent loops. They must be rock-solid: minimal CPU and memory overhead, zero tolerance for failure, and a developer experience that feels effortless. When you ship, thousands of developers benefit the same day.</p><h3>What You'll Do</h3><ul style="min-height:1.5em"><li><p style="min-height:1.5em"><strong>Own the Python and TypeScript SDKs end-to-end</strong> — reliability, performance, and developer experience. Set the bar for SDK quality across the organization.</p></li><li><p style="min-height:1.5em"><strong>Design APIs developers love</strong> — naming conventions, parameter structure, breaking-change communication, and documentation. Every detail of the DX is yours to shape.</p></li><li><p style="min-height:1.5em"><strong>Drive OpenTelemetry-based integrations</strong> — architect and implement framework integrations across the AI/LLM ecosystem (e.g. major LLM providers, orchestration frameworks, agent runtimes).</p></li><li><p style="min-height:1.5em"><strong>Maintain and evolve the SDK release lifecycle</strong> — versioning strategy, packaging, CI/CD pipelines, compatibility testing, and automated release management.</p></li><li><p style="min-height:1.5em"><strong>Performance engineer the SDK</strong> — profile, identify bottlenecks, and reduce latency and memory footprint so the SDK is never the limiting factor in production.</p></li><li><p style="min-height:1.5em"><strong>Engage the open-source community</strong> — triage GitHub issues, review external PRs, write developer-facing docs, and represent the project on public channels.</p></li><li><p style="min-height:1.5em"><strong>Collaborate cross-functionally</strong> — work closely with product and data teams to translate platform capabilities into clean SDK abstractions.</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, including 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 shipping production-grade SDKs — API design, versioning, packaging, and release management</p></li><li><p style="min-height:1.5em">Experience optimizing library 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 (OpenTelemetry experience is a strong plus)</p></li><li><p style="min-height:1.5em">Proficiency in <strong>Python and/or TypeScript/JavaScript</strong> and the ability to write idiomatic, language-specific library code</p></li><li><p style="min-height:1.5em">Active experience contributing to and maintaining open-source projects (GitHub issues, PR reviews, community interactions)</p></li><li><p style="min-height:1.5em">Strong written and verbal communication skills — comfortable writing docs, engaging with developers on GitHub, and participating in public technical discourse</p></li><li><p style="min-height:1.5em">Experience with automated testing and CI/CD pipelines for libraries (unit/integration tests, release automation, compatibility testing)</p></li><li><p style="min-height:1.5em">Ability to work effectively in a small, distributed team across EU timezones</p></li><li><p style="min-height:1.5em"><strong>Legal authorization to work in the EU is required — visa sponsorship is not available</strong></p></li><li><p style="min-height:1.5em">Ability to be onsite in Berlin approximately one week per month</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 databases such as ClickHouse)</p></li><li><p style="min-height:1.5em">Background from companies in the developer tooling, AI/ML infrastructure, or observability space</p></li><li><p style="min-height:1.5em">Bachelor's degree in Computer Science, Engineering, or equivalent practical experience</p></li></ul><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 per year, depending on experience and location</p></li><li><p style="min-height:1.5em">Equity participation in a well-funded, high-growth startup (Seed/Series A stage)</p></li><li><p style="min-height:1.5em">Flexible, remote-first work environment across Europe</p></li></ul><h3>Location</h3><p style="min-height:1.5em">This role is <strong>remote-friendly across Europe</strong> (team members are based in Germany, Austria, Switzerland, the Netherlands, France, Sweden, the UK, Spain, and Poland). You'll be expected to travel to <strong>Berlin, Germany</strong> for onsite collaboration approximately once per month. Candidates must be legally authorized to work in the EU — no visa sponsorship is available.</p><p>Find <a href="https://www.arbeitnow.com">Jobs in Germany</a> on Arbeitnow</a>