Braintrust

Braintrust was founded in 2023 by Ankur Goyal, a Carnegie Mellon-trained engineer who previously served as VP of Engineering at SingleStore and then founded Impira, a document-AI startup (with Richard Stebbing) that was acquired by Figma in 2023 (Goyal briefly served as Figma's Head of ML Platform after the acquisition). Drawing on his experience building AI-powered products, Goyal identified that teams shipping LLM applications lacked rigorous, systematic ways to measure and improve model quality -- what the industry calls 'evals.' Braintrust was built to make evaluation, tracing, and observability a first-class part of the AI engineering development loop, positioning 'eval-driven development' as an analogue to test-driven development in traditional software.

The company announced a $5.1M seed round in December 2023 (roughly $8.3M in total capital raised including a small preceding round), led by Greylock (Saam Motamedi) with participation from Elad Gil, Basecase Capital, SV Angel, Box Group, and a long list of operator-angels including OpenAI co-founder Greg Brockman, HuggingFace CEO Clem Delangue, Airtable CEO Howie Liu, Vercel CEO Guillermo Rauch, Notion CTO Simon Last, Zapier CTO Bryan Helmig, Datadog CEO Olivier Pomel, and others. Early customers cited in the seed announcement included Zapier, Coda, Airtable, and Instacart, with reported accuracy improvements of 30%+ within weeks of adopting the platform.

Braintrust raised a $36M Series A in October 2024, led by Martin Casado at Andreessen Horowitz, with continued participation from Greylock, Elad Gil, and Basecase, plus new strategic investors Datadog and Databricks Ventures. The round coincided with the launch of 'Functions,' a primitive letting developers define prompts, tools, and custom scorers as code and push/pull them between their codebase and the Braintrust UI. By this point the company reported that average users were running more than 10 experiments a day on the platform. In mid-2025 Braintrust shipped Brainstore, a purpose-built Rust database for AI trace/log data (claimed ~80x faster than prior infrastructure on real-world benchmarks), which became the default backend for hosted customers by March 2025.

Business model

B2B SaaS / developer platform, sold primarily to engineering teams building LLM/agentic applications; offered as hosted cloud product with self-hosted/hybrid deployment options for security-conscious enterprises (SOC 2 Type II certified).

Usage-based and seat/plan-based subscription pricing (Starter/paid tiers plus enterprise contracts), with usage-based add-ons (e.g., Topics token-based credits).