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, 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 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 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 #J-18808-Ljbffr