# Braintrust

> AI evaluation, observability, and prompt tooling for production LLM products.

## Why it is interesting

Used by Stripe, Notion, and Vercel for eval loops — a16z-led A with Greylock participation as evals become table stakes for shipping AI.

## Profile

- **Stage:** series-b
- **Status:** private
- **Industries:** ai-ml, developer-tools, enterprise-saas
- **Coverage:** full
- **Last updated:** 2026-07-24

## Key facts

- Series A (Oct 2024): $36M led by a16z for AI evals and LLM devtools (Braintrust blog)
- Series B: $80M with Greylock re-upping alongside a16z (company blog)
- Co-investors not in VCT directory: ICONIQ (Series B lead), Databricks Ventures, Datadog
- Source: https://www.braintrust.dev/blog/announcing-series-a

## Investors in our directory

- https://venturecapitaltracker.com/fund/andreessen-horowitz
- https://venturecapitaltracker.com/fund/greylock-partners

## Related articles

- https://venturecapitaltracker.com/2026-a16z-hot-portfolio-companies

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Source: https://venturecapitaltracker.com/startup/braintrust