SDK Engineer - Feature Flags

We're looking for a pragmatic polyglot engineer passionate about crafting high-quality developer experiences across a range of languages and platforms. You're someone who thrives on improving SDKs that developers enjoy using — ones that are fast, reliable, and feel native no matter the tech stack. In this role, you'll focus on our feature flag SDKs, used in server-side apps and infrastructure to power flag evaluation. Some of these SDKs make remote requests to our evaluation engine, while others run locally, meaning correctness and performance are equally critical. Many other PostHog products depend on the SDKs, so you'll be working on critical infrastructure that touches many parts of the company. You should be deeply familiar with at least one of our primary languages/platforms (Python, Go, Rust, C#, or TypeScript), and confident picking up enough of the others to make meaningful contributions across the SDK ecosystem. You'll work closely with backend, infra, and product teams to ensure our SDKs remain robust and delightful, while also helping us find ways to support more languages more efficiently.

We're equipping every developer to build successful products by giving them a suite of products to analyze, test, observe, and deploy new features. We currently offer product and web analytics, session replay, feature flags, experiments, a CDP, SQL access, a data warehouse, and LLM observability… and there's plenty more to come. PostHog was created as an open-source project during Y Combinator's W20 cohort. We had the most successful B2B software launch on HackerNews since 2012 with a product that was just 4 weeks old. Since then, more than 100,000 companies have installed the platform. We've had huge success with our paid upgrades, raised bags of money from some of the world's top investors, and have extremely strong product-led growth – 97% driven by word of mouth. We're growing quickly, but sustainably. We're also default alive, averaging 10% monthly revenue growth and with more than $20m ARR. We're staying focused on building an awesome product for end users, hiring a handful of exceptional team members, and seeing fantastic growth as a result.