# LLM observability & evals tools used by DevTools & Infrastructure companies usedby lists 17 DevTools & Infrastructure companies using 4 LLM observability & evals tools. The most used is Braintrust: 12 of the 17 DevTools & Infrastructure companies on usedby, every proof level counted. These are counts of the companies usedby tracks, not a market share. Data as of 2026-10-25. ## Ranking Tools ranked by the companies of the 17 DevTools & Infrastructure companies on usedby that use them. Each company counts once per tool, at its strongest proof. Ties go to more confirmed, then declared, then observed companies. | # | Tool | Companies | Confirmed | Declared | Observed | Job posts only | Last check | |---|---|---|---|---|---|---|---| | 1 | [Braintrust](https://www.usedby.ai/tools/braintrust.md) | 12 | 6 | 0 | 6 | 0 | 2026-10-25 | | 2 | [LangSmith](https://www.usedby.ai/tools/langsmith.md) | 3 | 0 | 0 | 3 | 0 | 2026-10-23 | | 3 | [Arize AI](https://www.usedby.ai/tools/arize-ai.md) | 2 | 1 | 0 | 1 | 0 | 2026-10-25 | | 4 | [Comet Opik](https://www.usedby.ai/tools/comet-opik.md) | 1 | 0 | 0 | 1 | 0 | 2026-10-21 | ## Customers per tool Every line is a customer, at one of three proof levels: confirmed (a case study, a named quote, a press release, or the company's own public account of using the tool (its own site, or a post by one of its executives, VP or above)), observed (the vendor shows the company on its own pages) or signal (a job post shows the company's employees use the tool, the weakest proof). A line the company declared to usedby itself is marked declared. A signal is never a case study or a vendor listing. Strongest proof first. "Last check" is the later of the line's re-verification and its latest capture. | Tool | Company | Proof | Source | Last check | |---|---|---|---|---| | Braintrust | [Dropbox](https://www.usedby.ai/companies/dropbox.md) | Confirmed | [braintrust.dev](https://www.braintrust.dev/customers/notion), captured 2026-10-25 | 2026-10-25 | | Braintrust | [Retool](https://www.usedby.ai/companies/retool.md) | Confirmed | [braintrust.dev](https://www.braintrust.dev/customers/retool), captured 2026-10-06 | 2026-10-25 | | Braintrust | [Box](https://www.usedby.ai/companies/box.md) | Confirmed | [braintrust.dev](https://www.braintrust.dev/customers/notion), captured 2026-10-25 | 2026-10-25 | | Braintrust | [Browserbase](https://www.usedby.ai/companies/browserbase.md) | Confirmed | [braintrust.dev](https://www.braintrust.dev/customers/browserbase), captured 2026-10-09 | 2026-10-25 | | Braintrust | [Bubble](https://www.usedby.ai/companies/bubble.md) | Confirmed | [braintrust.dev](https://www.braintrust.dev/customers/bubble), captured 2026-10-25 | 2026-10-25 | | Braintrust | [Graphite](https://www.usedby.ai/companies/graphite.md) | Confirmed | [braintrust.dev](https://www.braintrust.dev/customers/graphite), captured 2026-10-06 | 2026-10-25 | | Braintrust | [Airtable](https://www.usedby.ai/companies/airtable.md) | Observed | [braintrust.dev](https://www.braintrust.dev/pricing), captured 2026-10-25 | 2026-10-25 | | Braintrust | [Vercel](https://www.usedby.ai/companies/vercel.md) | Observed | [braintrust.dev](https://www.braintrust.dev/pricing), captured 2026-10-25 | 2026-10-25 | | Braintrust | [Replit](https://www.usedby.ai/companies/replit.md) | Observed | [braintrust.dev](https://www.braintrust.dev/pricing), captured 2026-10-25 | 2026-10-25 | | Braintrust | [Augment Code](https://www.usedby.ai/companies/augment-code.md) | Observed | [braintrust.dev](https://www.braintrust.dev/pricing), captured 2026-10-25 | 2026-10-25 | | Braintrust | [Greptile](https://www.usedby.ai/companies/greptile.md) | Observed | [braintrust.dev](https://www.braintrust.dev/pricing), captured 2026-10-25 | 2026-10-25 | | Braintrust | [Superhuman](https://www.usedby.ai/companies/superhuman.md) | Observed | [braintrust.dev](https://www.braintrust.dev/pricing), captured 2026-10-25 | 2026-10-25 | | LangSmith | [Autodesk](https://www.usedby.ai/companies/autodesk.md) | Observed | [langchain.com](https://www.langchain.com/langsmith/observability), captured 2026-10-23 | 2026-10-23 | | LangSmith | [GitLab](https://www.usedby.ai/companies/gitlab.md) | Observed | [langchain.com](https://www.langchain.com/langsmith/customers) | Not dated | | LangSmith | [Factory](https://www.usedby.ai/companies/factory.md) | Observed | [langchain.com](https://www.langchain.com/customers), captured 2026-10-23 | 2026-10-23 | | Arize AI | [PagerDuty](https://www.usedby.ai/companies/pagerduty.md) | Confirmed | [arize.com](https://arize.com/customers/pagerduty-ai-agent-quality-monitoring/), captured 2026-10-16 | 2026-10-25 | | Arize AI | [Atlassian](https://www.usedby.ai/companies/atlassian.md) | Observed | [arize.com](https://arize.com/customers/), captured 2026-10-25 | 2026-10-25 | | Comet Opik | [Autodesk](https://www.usedby.ai/companies/autodesk.md) | Observed | [comet.com](https://www.comet.com/site/), captured 2026-10-21 | 2026-10-21 | ## Method Public customer lines of active LLM observability & evals tools at companies classified in DevTools & Infrastructure. No software vendor had to be left out. Company mix by strongest proof: 7 confirmed, 0 declared, 10 observed and 0 signals. ## Questions ### Which LLM observability & evals tools do DevTools & Infrastructure companies use most? Braintrust leads: 12 of the 17 DevTools & Infrastructure companies on usedby that use LLM observability & evals tools use it. Next: LangSmith (3), Arize AI (2), and Comet Opik (1). ### How many DevTools & Infrastructure companies use LLM observability & evals tools? 17 DevTools & Infrastructure companies on usedby use at least one of 4 LLM observability & evals tools. It counts the companies usedby tracks. ### What proof backs these lines? Of the 17 companies, each counted at its strongest proof: 7 confirmed, 0 declared, 10 observed and 0 known from a job post. ### How does usedby build this ranking? usedby counts each DevTools & Infrastructure company once per tool, from public proof: case studies, press releases, the company's own site or its declaration to usedby, vendor customer pages and job posts. Every line shows its proof and the date usedby last checked it. Industry page: https://www.usedby.ai/companies/industry/devtools-infrastructure.md · Category page: https://www.usedby.ai/tools/category/llm-observability-evals.md --- Source: https://www.usedby.ai/companies/industry/devtools-infrastructure/llm-observability-evals · How we check: https://www.usedby.ai/methodology