Langfuse - Senior Backend Engineer

Why Backend Engineering at Langfuse

Langfuse ingests terabytes of AI tracing data per day. The core of your role is making Langfuse fast and affordable at scale: owning the ingestion pipeline, optimizing ClickHouse data models and queries so dashboards load instantly, and building the backend abstractions that let product engineers ship data-heavy features without reinventing the plumbing each time. Langfuse is now part of ClickHouse, giving direct access to the team that built the database you're optimizing.

You Will Grow at Langfuse By

• Owning and optimizing the ingestion pipeline: working on throughput, latency, reliability, and cost efficiency at every stage
• Making ClickHouse fast: designing schemas, optimizing merge strategies, tuning batch inserts, writing and reviewing analytical queries
• Building new infrastructure-heavy features like LLM-as-a-Judge, alerting at scale, client-code execution, or batch dataset operations
• Testing with real data in production: running load tests against production data to validate that changes actually improve things
• Scaling for what's next as new product directions like agent observability push the infrastructure in new ways

What We're Looking For

• Strong backend engineer who gets excited about database internals, query optimization, and distributed systems
• Experience with analytical databases, data pipelines, or high-throughput event processing (ClickHouse experience is a big plus but not required)
• Comfortable reading and writing TypeScript (the backend) and SQL
• Interest in open source software and genuine enjoyment talking to users about their scaling challenges

Bonus points: Experience with ClickHouse, other OLAP databases, or observability infrastructure; background in building data-intensive systems at scale.

Perks

Flexible work environment - ClickHouse is a globally distributed company and remote-friendly, operating in over 25 countries. Healthcare employer contributions, equity in the company, flexible time off, a USD$500 home office setup for remote employees, and Global Gatherings for in-person connection at company-wide offsites.

Compensation

€90K – €160K, offers equity.