Braintrust is the AI observability platform. By connecting evals and observability in one workflow, Braintrust gives builders the visibility to understand how AI behaves in production and the tools to improve it. Teams at Notion, Stripe, Zapier, Vercel, and Ramp use Braintrust to compare models, test prompts, and catch regressions — turning production data into better AI with every release. About the Role We’re hiring engineers to build the open-source libraries that customers use to observe, understand, and optimize how AI operates inside their production applications. These SDKs are a critical part of Braintrust’s platform. They power evaluation and observability pipelines across a wide range of environments, frameworks, and AI providers. This role is ideal for engineers who are passionate about developer experience, API craftsmanship, and building fast, reliable, and idiomatic libraries. You’ll own the full SDK lifecycle: design, implementation, release, documentation, and community support. Your work will be embedded in thousands of applications and help define how AI is adopted and operationalized across industries.