Langfuse is building open-source observability and product analytics for LLM applications. We help engineers and companies understand how customers use their LLM applications and how they can improve on them. Have a look at our website and especially technical docs to learn more.

Customer Success Engineer at Langfuse

TLDR; Langfuse builds open-source developer tooling for LLM applications, centered on observability and tracing. We have strong traction, are default alive, and growing fast. We’re now looking for a Customer Success Engineer to join our team in person in San Francisco or Berlin.

Langfuse is the open-source LLM engineering platform that helps engineers understand user interactions with LLM apps and improve them. We work with customers like Twilio, SumUp, and Khan Academy, and are backed by Y Combinator, Lightspeed, and General Catalyst. Tens of thousands of engineers rely on Langfuse — learn more about us at langfuse.com and our handbook.

Your Role

As an early customer success hire, you’ll shape how Langfuse partners with users and customers to ensure successful onboarding, adoption, and long-term growth. You’ll work closely with founders, engineering, and GTM teams to help technical users get the most out of Langfuse.

Customer Success & Enablement

• Help new users and customers onboard and succeed with Langfuse.
• Provide hands-on guidance and best practices for LLM observability and evaluation.
• Serve as the main point of contact for technical and operational questions.
• Track product adoption and proactively reach out to help customers deepen usage.
• Identify upsell opportunities and contribute to retention and growth.

Customer Insights & Product Feedback

• Translate customer needs into actionable product feedback.
• Build and maintain feedback loops between users, success, and product teams.
• Help shape documentation and learning resources to reduce friction.

Systems & Process

• Build and maintain workflows for tracking adoption, success metrics, and customer health.
• Document playbooks, best practices, and internal tooling for the success function.
• Partner with sales and product to align priorities across the user lifecycle.

Requirements

• Experience in customer success, solutions engineering, or technical account management at a SaaS/devtool company.
• Strong technical aptitude — able to understand APIs, logs, and developer workflows.
• Excellent communication and problem-solving skills.
• Comfortable working cross-functionally in a fast-moving startup.
• Willingness to work in-person ~4 days/week.

Bonus Points

• You’ve used Langfuse (sign up for a free account here).
• Familiarity with open-source or developer-focused products.
• Experience supporting or building with LLM/AI tools.
• Entrepreneurial mindset — you enjoy building new processes and solving ambiguous problems.

Why Langfuse?

• Work with sophisticated technical users and top engineering teams.
• Competitive salary & equity.
• Rapid customer and revenue growth.
• Join early and shape the company’s culture and processes.
• Extreme autonomy and focus on outcomes.
• Team culture described by everyone as “the best place I’ve ever worked.”
• Only two short scheduled meetings per week.

Team & Culture

You’ll join our early core team, working closely with founders Clemens (COO, sales) and Marc (CEO, product/marketing). Clemens is based in San Francisco, Marc in Berlin. We prioritize in-office collaboration, learning, and ownership.

Learn more about us at langfuse.com/handbook.

https://github.com/langfuse/langfuse/

Stack: Frontend and Backend in Typescript (T3 Stack including NextJs, Tailwind, Prisma, tRPC), Postgres, Client facing SDKs in Python and Typescript