Built by ex-Stripe engineers for AI teams that ship

Braintrust came out of YC W23 with a focused thesis: every serious AI product needs an eval-driven dev loop, and existing tools (LangSmith, Helicone) are observability-first, not eval-first. In 2026, Braintrust is the platform of choice for AI engineering teams at Notion, Stripe, Zapier, and Ramp — exactly the kinds of teams where 'did my prompt change break production?' is a million-dollar question.

Who it's for: AI/ML engineering teams shipping LLM products to production who need rigorous offline + online evals.

Key features

Evals Offline + online scoring

Run evals across your full prompt/model matrix. Custom scorers (LLM-as-judge, code, human). Per-PR scores in CI.

Tracing Span-level visibility

Capture every LLM call, tool use, and retrieval. OpenTelemetry-native. Debug slow chains or runaway costs.

Datasets Golden test sets

Version, slice, and grow your eval datasets. Auto-generate synthetic test cases from production traffic.

Experiments Prompt A/B testing

Compare prompts/models side-by-side. Surface regressions before they hit prod. PR-level summaries.

Logs Production observability

Stream prod traces, attach user feedback, and surface failure patterns. SOC 2 + HIPAA + EU residency.

The honest take

✓ What works

Best-in-class evals — the platform is eval-first, not observability-first
Per-PR scores — your CI catches prompt regressions before merge
Supports all major models (OpenAI, Anthropic, Gemini, OSS) with one SDK
Braintrust Data is genuinely useful — store labeled data + iterate on it
Enterprise-ready: SOC 2, HIPAA, EU residency on paid tiers

✗ What doesn't

Free tier is generous (5K traces) but Team ($249/mo) is the real unlock — pricey for startups
Steeper learning curve than Helicone — bring engineering bandwidth
UI can feel overwhelming at first — lots of features to learn
Self-hosting is not offered (cloud-only)

Verdict

Braintrust is the right pick if you're shipping LLM features to production and need to know whether they got better or worse. The eval loop alone justifies the price for teams of 5+ engineers. For solo devs or hobby projects, start with Helicone (lighter weight).

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