Software Engineer, Backend

ABOUT THE COMPANY 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, and Vercel use Braintrust to compare models, test prompts, and catch regressions — turning production data into better AI with every release. ABOUT THE ROLE We’re looking for a backend engineer who’s excited to build the infrastructure behind cutting-edge AI development tools. Under the hood, Braintrust is a real-time, high-availability data platform that operates in both SaaS and self-hosted environments. You’ll help scale our ingestion pipelines, evolve our open source libraries, and ensure everything runs reliably, observably, and fast. If you thrive in a fast-paced environment and enjoy solving hard systems problems with a product mindset, we’d love to work with you. WHAT YOU'LL DO As a backend engineer at Braintrust, you’ll help build the core platform powering LLM-native development: - Design and ship features that give users deep insight into their LLM usage and performance. - Integrate, proxy, cache, and collect data from OpenAI, Anthropic, Gemini, and other major model providers that our customers rely on. - Develop and evolve robust, efficient open source libraries for tracing and evaluating LLM calls inside custome...