Top all-time · #5265
Langfuse: Open Source Agent Evals & Observability
Company blog · langfuse.com · on HN as mdeichmannaiprogramming
Langfuse: Open Source Agent Evals & Observability is the company blog at langfuse.com, writing about ai and programming. Since 2023, 15 different Hacker News readers have linked it 59 times, most often “Roast My Docs”. No feed was found, so read it on the site itself.
Too few sampled comments (12) to say how often HN recommends it.?
Why HN links it
HN readers link Langfuse's blog for its v3 infrastructure write-up and its upgrade guide for the ClickHouse migration. The posts cover the company's open-source LLM observability and evals platform.
Summarised by Claude from a sample of 12 HN comments that link here. Each comment is marked recommending, critical or neutral (citing without judging); how this works.
Trace, evaluate, and improve AI agents with one open platform. Use production data to understand behavior, collaborate on fixes, and ship better quality at lower cost and latency.
Most-linked posts?
- /careers2 people · 7 mentions · first linked 2023-11-01
- Roast My Docs2 people · 2 mentions · first linked 2024-04-17
- Langfuse v3 Infrastructure Evolution2 people · 2 mentions · first linked 2025-01-27
- OSS Decorator to Trace LLM Apps – Integrated with LlamaIndex, LangChain, OAI SDK2 people · 2 mentions · first linked 2024-04-24
- ClickHouse Acquires Langfuse2 people · 2 mentions · first linked 2026-01-16
What Hacker News says?
Langfuse | Backend Engineer, Product Engineer, Devrel | Berlin Germany | in-person | Full-time I'm Clemens, co-founder of Langfuse (YC W23) - we're building open source LLMOps dev tooling (Github: https://github.com/langfuse/langfuse/ ). We started with observability and have branched out into more workflows over time (evals, prompt mgmt, playground, testing...). We have a bunch of traction and are looking for our t…
Comment linking /careers
on “Ask HN: Who is hiring? (July 2024)”Submitted Doubling Down on Open Source as a story · 137 points
HN discussionLangfuse ( https://langfuse.com ) | Backend Engineer, Product Engineer, Design Engineer | Berlin Germany | in-person | Full-time I'm Max, co-founder and CTO of Langfuse (YC W23) - we're building open source LLMOps dev tooling (Github: https://github.com/langfuse/langfuse/ ). We started with observability and have branched out into more workflows over time (evals, prompt mgmt, playground, testing...). We have a bunch…
Comment linking /careers
on “Ask HN: Who is hiring? (February 2025)”Submitted Building (Open Source) Custom Dashboards Is Harder Than You Think as a story · 33 points
HN discussionLangfuse | Backend Engineer, Product Engineer, Devrel | Berlin Germany | in-person | Full-time I'm Clemens, co-founder of Langfuse (YC W23) - we're building open source LLMOps dev tooling (Github: https://github.com/langfuse/langfuse/ ). We started with observability and have branched out into more workflows over time (evals, prompt mgmt, playground, testing...). We have a bunch of traction and are looking for our t…
Comment linking /careers
on “Ask HN: Who is hiring? (June 2024)”Submitted ClickHouse Acquires Langfuse as a story · 21 points
HN discussionLangfuse | Backend Engineer, Product Engineer, Devrel | Berlin Germany | in-person | Full-time I'm Clemens, co-founder of Langfuse (YC W23) - we're building open source LLMOps dev tooling (Github: https://github.com/langfuse/langfuse/ ). We started with observability and have branched out into more workflows over time (evals, prompt mgmt, playground, testing...). We have a bunch of traction and are looking for our t…
Comment linking /careers
on “Ask HN: Who is hiring? (August 2024)”Submitted Documentation Is Product as a story · 8 points
HN discussionThrough one of such posts I found this blogpost - https://langfuse.com/blog/2024-12-langfuse-v3-infrastructure... which to me was very interesting. Maybe you should include it in your job description.
Comment linking /blog/2024-12-langfuse-v3-infrastructure-evolution
on “Ask HN: Who is hiring? (April 2025)”Submitted Roast My Docs as a story · 8 points
HN discussionLangfuse ( https://langfuse.com ) | Backend Engineer, Product Engineer, Design Engineer | Berlin Germany | in-person | Full-time I'm Max, co-founder and CTO of Langfuse (YC W23) - we're building open source LLMOps dev tooling (Github: https://github.com/langfuse/langfuse/ ). We started with observability and have branched out into more workflows over time (evals, prompt mgmt, playground, testing...). We have a bunch…
Comment linking /careers
on “Ask HN: Who is hiring? (April 2025)”Submitted Langfuse (YC W23) Open sourced their roadmap for LLMops as a story · 7 points
HN discussionWe’re hiring at Langfuse — now part of ClickHouse. We are looking for a Product Manager, Product & Backend Engineers, Product Marketing Manager and Developer Relations Engineers to join us in building the most widely adopted open-source LLM engineering platform. - Berlin or EU hybrid (Engineering roles) / US-fully remote (Product & Marketing roles) - ~1 week onsite in Berlin every 2 months — travel covered - Full-ti…
Comment linking /docs
on “Ask HN: Who is hiring? (September 2026)”Submitted Langfuse – LLM Engineering Platform – Traces, evals, prompt scoring and metrics as a story · 6 points
HN discussionThanks! Really enjoyed working with you maintainers of other projects to help them offer more native LLM observability and evaluation to their users/communities. There is a lot that goes into making the observability/eval part scalable/useful and requirements change on a weekly basis with new advancements. Same applies to other projects and it makes a lot of sense to integrate. Overview of community integrations: ht…
Comment linking /faq/all/packages-depending-on-langfuse
on “Launch HN: Langfuse (YC W23) – OSS Tracing and Workflows to Improve LLM Apps”Submitted OSS Decorator to Trace LLM Apps – Integrated with LlamaIndex, LangChain, OAI SDK as a story · 6 points
HN discussionthank you! if you have any ideas for improvements after having used Langfuse for a while, please contribute them via github discussions: https://langfuse.com/ideas
Comment linking /ideas
on “Launch HN: Langfuse (YC W23) – OSS Tracing and Workflows to Improve LLM Apps”Submitted OSS Observability for Vercel AI SDK as a story · 6 points
HN discussionThanks for the feedback. Being unopinionated and API-first has been a core design decision. We want to build the building blocks that everyone needs while acknowledging that most Langfuse users are very sophisticated teams that have a clear idea of what they want to achieve. Over time we will build more abstractions for common workflows to make it easier to get started but new features will always start API-first. M…
Comment linking /why
on “Launch HN: Langfuse (YC W23) – OSS Tracing and Workflows to Improve LLM Apps”Submitted Scoping and curating AI eval datasets as a story · 3 points
HN discussionThanks, this post was insightful. I laughed at the reason why you rejected Arize Phoenix, I had similar thoughts while going through their site!=) > "Another notable feature of Langfuse is the use of a model as a judge ... this is not enabled in the free version/self-hosted version" I think you can add LLM-as-judge to the self-hosted version of Langfuse by defining your own evaluation pipeline: https://langfuse.com/…
Comment linking /docs/scores/external-evaluation-pipelines
on “Launch HN: Langfuse (YC W23) – OSS Tracing and Workflows to Improve LLM Apps”Submitted How we run untrusted code in Langfuse (OSS) and why we picked lambda as a story · 3 points
HN discussionPositioning/roadmap differs between the different project in the space. We summarized what we strongly believe in here: https://langfuse.com/why Tldr: open apis, self-hostable, LLM/cloud/model/framework-agnostic, API first, unopinionated building blocks for sophisticated teams, simple yet scalable instrumentation that is incrementally adoptable Regarding roadmap, this is the near-term view: https://langfuse.com/road…
Comment linking /ideas
on “Launch HN: Langfuse (YC W23) – OSS Tracing and Workflows to Improve LLM Apps”Submitted Trace your local Ollama model with Langfuse as a story · 3 points
HN discussionThis is an optional instrumentation of the OpenAI SDK which simplifies getting started, tracking token counts, model parameters and streaming latencies. Langfuse is not in the critical path, this just helps with instrumentation. You can use the Langfuse Python SDK / Decorator to track any LLM (with some instrumentation code) or use one of the framework integrations. Here is a fully-featured example using the Amazon…
Comment linking /docs/integrations/amazon-bedrock
on “Launch HN: Langfuse (YC W23) – OSS Tracing and Workflows to Improve LLM Apps”Submitted Trace complex LLM applications with the Langfuse decorator (Python) as a story · 3 points
HN discussionI've been keeping a rolling list of LLMOps/AI agent observability products funded by YC. What problems does Lucidic solve that the others do not? https://hegel-ai.com https://www.vellum.ai/ https://www.parea.ai http://baserun.ai https://www.traceloop.com https://www.trychatter.ai https://talc.ai https://langfuse.com https://humanloop.com https://uptrain.ai https://athina.ai https://relari.ai https://phospho.ai https…
Comment linking /
on “Launch HN: Lucidic (YC W25) – Debug, test, and evaluate AI agents in production”Submitted Capturing Implicit Feedback from Users as a story · 2 points
HN discussionThis is interesting! Do you plan to add support for distinguishing between blocking and non-blocking/async migrations? This seems to be a common challenge when using Clickhouse and needing to change the ordering of existing tables. Context: When adding Clickhouse to Langfuse [1] to store all observability data, the migration DX was a big challenge. Some migrations need to copy/reorder data between tables which can t…
Comment linking /self-hosting/background-migrations
on “Show HN: Houseplant – Database Migrations for ClickHouse”Submitted Langfuse v4: agent evals and traces rebuilt on one immutable ClickHouse table as a story · 2 points
HN discussion