YCW23· AI· Data· DevtoolsLangfuse
Open source LLM engineering platform
Founders
Not read from YC yet; the weekly run fills these in.
Same space
Competitors
Closest in what they build, same category.
Confident AIW25The LLM Eval and Observability Platform for AI QualityShared: developer tools, open sourceActive
HyperDXS22Open-source, dev-friendly observability.Shared: developer tools, open sourceAcquired
HeliconeW23LLM Observability for DevelopersShared: developer tools, analytics, open sourceAcquired
ElementaryW22Open-source data observability for data teamsShared: developer tools, analytics, open sourceActive
SigNozW21Open source alternative to DataDogShared: developer tools, open sourceActive
Adjacent
Overlapping tags, a different niche.
GrowthBookW22Open source feature flagging and A/B testingShared: developer tools, analytics, open sourceActive
LightdashS20The open source Looker alternativeShared: developer tools, analytics, open sourceActive
GraiS22Open source version control for metadataShared: developer tools, analytics, open sourceInactive
ParadeDBS23Unify application data, vectors, and full-text search in one PostgresShared: developer tools, analytics, open sourceActive
HydraW22Serverless Analytics on PostgresShared: developer tools, analytics, open sourceAcquired
Also from W23 in AI
Batchmates in Winter 2023.
DAGWorks Inc.W23Open source tools & services for reliable AI Agents & AI ApplicationsAcquired
FernW23Instantly offer SDKs and API DocsAcquired
LiteLLMW23Call every LLM API like it's OpenAI [100+ LLMs]Active
OpenIntW23Open Source Embedded Product IntegrationsAcquired
OuterbaseW23The interface for your databaseAcquired
ReflexW23The operating system for building mission-critical enterprise apps.Active
Across fru.dev
About Langfuse
Traces, evals, prompt management and metrics to debug and improve your LLM application. Onboard via https://langfuse.com Langfuse helps you build and improve LLM applications across the entire lifecycle: - Develop: Observability, Langfuse UI & Prompt Management - Monitor: Traces, Analytics, Metrics & Evaluations - Test: Experiments, Releases & Datasets We are hiring: https://langfuse.com/careers Langfuse was acquired by Clickhouse in January of 2026.
Berlin, Berlin, Germany
Langfuse: questions
Which YC batch was Langfuse in?
Langfuse was in Y Combinator's Winter 2023 batch (W23).
Is Langfuse still active?
Y Combinator lists Langfuse as acquired.
Where is Langfuse based?
Langfuse lists Berlin, Berlin, Germany as its location on YC's directory.
Not affiliated with Y Combinator. From YC's public directory. Logos via logo.dev; trademarks belong to their owners.