Langfuse

Backed byY Combinator
Total raised$4.0M
StageSeed
Hiring pace2 roles / 90d
Founded2022
Team size11-50
HQSan Francisco
IndustriesSaaSDeveloper ToolsAIAnalyticsOpen Source

About Langfuse

Langfuse is the open-source LLM engineering platform designed to help teams build production-grade LLM applications faster.Langfuse addresses these challenges by providing an open-source platform to debug and improve LLM applications. Langfuse captures the full context of your application, tracing the complete execution flow—including API calls, retrieved context, prompts, parallelism, and more. By enabling hierarchical representations through nested traces, Langfuse helps you understand complex logic built around LLM calls. Langfuse also offers full **multi-modal** support, including audio, images, and attachments.Metrics & QualityLangfuse measures cost and latency, breaking down metrics by user, session, feature, model, and prompt version, allowing for detailed analysis. To assess output quality, Langfuse facilitates the collection of user feedback, performs automated LLM-as-a-judge evaluations, and supports manual data labeling within the platform. It also offers **prompt management** features, allowing you to handle prompts effectively and perform **prompt experiments** over new ideas and systematically track success.Testing & ExperimentationFor testing and experimentation, Langfuse supports versioning your application and running tests of expected inputs and outputs via curated datasets. This provides quantitative insights into the impact of changes, helping you understand and improve your LLM applications more effectively.

Open positions · 2

Company at a glance

Location
San Francisco
LinkedInLinkedIn

Founders & Leadership

CR

Clemens Rawert

co-founder Langfuse (now part of ClickHouse)

LinkedIn
MK

Marc Klingen

Co-founder & CEO langfuse.com, YC W23, OSS LLM Engineering Platform

LinkedIn
MD

Max Deichmann

co-founder & CTO at langfuse.com (YC W23)

LinkedIn
MM

Marlies Mayerhofer

Founding Engineer at Langfuse | MS CS Imperial College

LinkedIn

Location

Why Clera highlights Langfuse

Top Tier InvestorsOpen SourceAmbitious TeamRapid Growth

About the Team

Team Distribution

  • Engineering63%
  • Leadership19%
  • Sales13%
  • Operations6%

Where the Team Studied

  1. 1.Technical University of Munich
  2. 2.The London School of Economics and Political Science
  3. 3.University of Mannheim
  4. 4.University of California, Berkeley
  5. 5.WHU – Otto Beisheim School of Management

Team Worked At

  • Google
  • Microsoft
  • Fraunhofer AISEC
  • Snowflake
  • McKinsey & Company

Team Composition

14 people
  • Engineering1 senior8
  • Entrepreneurship3 senior3
  • Business Development1

Funding History

SeedNov 2023

$4M

raised

Open-source LLM observability platform Langfuse raised a $4M seed round from Lightspeed Venture Partners, La Famiglia and Y Combinator

Y CombinatorLightspeed Venture PartnersLa Famiglia

Life at Langfuse

Frequently asked questions

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