Langfuse Blog

Langfuse (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 of traction and are looking for our fourth to sixth hire in scaling and building feature depth. We're hiring in person (4-5 days/week) in Berlin, Germany (salary ranges for each job 70k-130k, up to 0.35% equity). We value quality in engineering at Langfuse: We try to find elegant solutions to complex engineering challenges, and we invested significant effort in enhancing our production setup (infra as code, top observability setup and more). If you'd love shipping in open source, writing about what you work on and working hard with super interesting and sophisticated customers (devs) - reach out! More info: https://langfuse.com/careers

Thanks, 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/docs/scores/external-evaluation-pipelines

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 third to fifth hire in scaling and building feature depth. We're hiring in person (4-5 days/week) in Berlin, Germany (salary ranges for each job 70k-130k, up to 0.75% equity). If you'd love shipping in open source, writing about what you work on and working hard with super interesting and sophisticated customers (devs) - reach out! We're particularly looking for a backend engineer that can help with Clickhouse and a product engineer that will work full-stack on shipping features end-to-end while staying close to our users. Feel free to ping me via clemens@ More info: https://langfuse.com/careers

Ah, the painful migration to Clickhouse from v2 to v3 makes sense now https://langfuse.com/self-hosting/upgrade/upgrade-guides/upgrade-v2-to…

I'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://github.com/BerriAI/bettertest https://www.getzep.com https://hamming.ai https://github.com/DAGWorks-Inc/burr https://www.lmnr.ai https://keywordsai.co https://www.thefoundryai.com https://www.usesynth.ai https://www.vocera.ai https://coval.ai https://andonlabs.com https://lucidic.ai https://roark.ai https://dawn.so/ https://www.atla-ai.com https://www.hud.so https://www.thellmdatacompany.com/ https://casco.com https://www.confident-ai.com

Through one of such posts I found this blogpost - https://langfuse.com/blog/2024-12-langfuse-v3-infrastructure-evolution which to me was very interesting. Maybe you should include it in your job description.

This 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 take a long time and thus need be performed in the background/async. Many teams run Langfuse self-hosted and reducing downtime of an upgrade is important, thus, we added some custom logic to run these “background migrations” for now [2]. For regular migrations we use golang-migrate, works decently although DX isn’t as good as eg Prisma for Postgres. [1] OSS LLM Observability, https://github.com/langfuse/langfuse [2] https://langfuse.com/self-hosting/background-migrations