# Braintrust

**Source:** https://geo.sig.ai/brands/braintrust  
**Vertical:** Developer Tools  
**Subcategory:** AI Observability & Evaluation  
**Tier:** Challenger  
**Website:** braintrust.dev  
**Last Updated:** 2026-04-15

## Summary

AI observability and eval platform for production AI. $800M valuation after $80M Series B (Feb 2026). Clients: Notion, Cloudflare, Ramp. Founded 2023, SF. Private.

## Company Overview

Braintrust is an AI observability and evaluation platform founded in 2023 by Ankur Goyal in San Francisco. The platform enables engineering teams to build, test, monitor, and improve AI products by providing tools for prompt engineering, dataset versioning, automated scoring, trace inspection, and quality measurement. Goyal previously founded Impira (acquired by Figma) and led Figma's AI team.

Unlike traditional application monitoring tools, Braintrust is purpose-built for AI workflows, offering an evaluation-first development approach where every code change is tested against quality benchmarks before deployment. The platform includes a collaborative prompt playground, side-by-side model comparison, and version-controlled eval infrastructure. Its customer base includes Notion, Replit, Cloudflare, Ramp, Dropbox, Vercel, Navan, and BILL.

In February 2026, Braintrust raised $80 million in Series B funding led by ICONIQ Capital, with participation from Andreessen Horowitz, Greylock, and Basecase Capital, valuing the company at $800 million. Total funding reached $121M. The rapid valuation growth from $150M to $800M reflects surging enterprise demand for AI observability tooling.

## Frequently Asked Questions

### What is Braintrust?
Braintrust is an AI observability and evaluation platform that helps engineering teams monitor, test, and improve the quality of AI products in production.

### How much funding has Braintrust raised?
Braintrust has raised $121 million total: $5M seed (2023), $36M Series A (2024), and $80M Series B (Feb 2026) at an $800M valuation.

### Who uses Braintrust?
Major customers include Notion, Replit, Cloudflare, Ramp, Dropbox, Vercel, Navan, and BILL.

### Who founded Braintrust?
Braintrust was founded in 2023 by Ankur Goyal, who previously founded Impira (acquired by Figma) and led the AI team at Figma.

### How is Braintrust different from traditional monitoring tools?
Unlike traditional APM tools, Braintrust is purpose-built to monitor AI model output quality, detecting hallucinations, content drift, and regression specific to generative AI.

### What does Braintrust's evaluation platform actually measure?
Braintrust evaluates AI application quality across dimensions like factual accuracy, hallucination rate, task completion, tone, and custom business metrics. Teams define evaluation criteria as code-based scorers — using LLM-as-judge, human review, or rule-based checks — and run them on test datasets, golden sets, and live production samples to catch regressions before and after model or prompt changes.

### How does Braintrust's proxy work?
Braintrust's AI proxy routes LLM API calls through Braintrust's infrastructure, automatically logging every prompt and completion for observability. This gives teams a full audit trail of AI calls in production — including latency, cost, input/output, and model version — without any changes to application code beyond swapping the API base URL. Semantic caching is also available to reduce redundant API calls and costs.

### What is Braintrust's open-source strategy?
Braintrust's evaluation SDK (braintrust-sdk) is open source, allowing teams to run evals locally without a Braintrust account. The commercial platform adds managed infrastructure for storing traces and experiments at scale, team collaboration features, production monitoring, and enterprise access controls. This open-core model has driven adoption — the SDK has been integrated into major LLM frameworks including LangChain and LlamaIndex.

## Tags

b2b, developer-tools, platform, saas

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*Data from geo.sig.ai Brand Intelligence Database. Updated 2026-04-15.*