ABOUT THE COMPANY Braintrust is the agent observability platform. By actively applying intelligence to agent traces and automatically surfacing the most critical patterns, Braintrust gives teams the visibility to understand how agents behave in production and the tools to improve them. Teams at Notion, Stripe, Box, OpenAI, and Cloudflare use Braintrust to trace their agents, find the issues in their observability data, and run evals that tell them how to improve. 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. * Build from scratch the unifying layer that proxies, caches, and normalizes calls across OpenAI, Anthropic, Gemini, and every other provider our customers depend on. * Develop and evolve robust, efficient open source libraries for tracing and evaluating LLM calls inside customer applications. Check out our SDKs * Build highly available real-time data pipelines to ingest, store, and query large volumes of structured and semi-structured AI usage data. You will also collaborate closely with our product engineers to ship polished, end-to-end features that solve real problems for our customers, such as: * Bundling and uploading javascript and python code snippets to be used as online, on-demand function calls for LLM workflows. * Support for parsing and uploading attachments from LLM multimodal outputs into long term storage. * Role-based access controls and data retention policies for enterprise use cases. IDEAL CANDIDATE CREDENTIALS * 5+ years of backend engineering experience across multiple parts of the stack * Strong systems thinking: you’ve owned or contributed to infrastructure projects and know how to design for scale, uptime, and data integrity * Proficient in modern backend technologies (e.g., Node.js, Go, Python, Rust, Postgres, Redis, Terraform, Docker, AWS) * Experience with observability tooling (e.g., Grafana, Prometheus, Datadog, or similar) and a passion for making systems operable, available and rock solid.   * Comfortable with ambiguous problems and excited to partner across the company to ship impactful work * Clear communicator who documents decisions, shares context, and helps lift the team BENEFITS INCLUDE * Medical, dental, and vision insurance * Daily lunch, snacks, and beverages * Flexible time off * Competitive salary and equity * Wifi & cellphone stipend EQUAL OPPORTUNITY Braintrust is an equal opportunity employer. All applicants will be considered for employment without attention to race, color, religion, sex, sexual orientation, gender identity, national origin, veteran or disability status.