Humanloop

Humanloop was an enterprise LLM development platform founded in 2020 as a UCL spinout, offering prompt management, evaluations, and observability tools for teams building AI applications. With customers like Duolingo and Gusto, it raised ~$8M and reached ~$3.8M ARR before being acqui-hired by Anthropic in August 2025, after which the platform was sunsetted on September 8, 2025. Its technology and team live on inside Anthropic's enterprise console.