AI​/LLM Engineer

About Mercura

Mercura is building AI software for the backbone of our economy.

Backed by Y Combinator, we raised a heavily oversubscribed round at one of the highest valuations in our cohort. As one of Europe's fastest growing startups, we surpassed $2M in ARR in our first year
. Now, we are looking for team members ready to go all-in to help us reach our next milestone: $10M ARR by the end of 2026
.

One of our co-founders, Lukas, grew up in a trades family that has been active in the construction industry for over 115 years. Having worked on the construction site himself, he learned first‑hand how slow and manual quoting still is in the industry.

In an era where AI becomes ubiquitous, we set out on a deeply personal mission: bring AI to the backbone of our economy - to the companies that keep our world running. To amplify human expertise and free people to do what only humans can do.

As an AI/LLM Engineer
, you will play a key role in building agentic AI systems end-to-end
. This is a fast‑paced, hands‑on role for engineers with high agency, strong technical depth and founder mindset. You’ll work on building reliable AI systems in production - from retrieval and LLM orchestration to tool‑using agents and product integration.

If you’re a passionate builder who excels at the intersection of LLMs, data systems, AI, data engineering, and full‑stack development
, this is your opportunity to shape how users interact with AI in real‑world workflows.

• Agentic Systems: Design and build LLM-powered agentic systems end-to-end, from experimentation to production deployment
• Retrieval & Context :
  Build retrieval and context pipelines (RAG, hybrid search, structured retrieval) to enable reliable reasoning over large volumes of technical and commercial data
• AI Evals :
  Develop evaluation and monitoring systems to measure and improve AI performance in production
• Data Pipelines :
  Build scalable pipelines to process and structure large volumes of unstructured documents and data
• Feedback Loops :
  Implement automated feedback pipelines that allow AI systems to learn from usage data and human feedback
• AI Infra :
  Own the architecture and reliability of AI systems in production, ensuring they are fast, scalable, and robust
• Product Integration :
  Collaborate with other stellar engineers to deeply integrate AI capabilities into the product experience

• Learn to build a company: Over five Mercura alumni have gone on to found their own companies and raise millions after their time with us. At Mercura, you’ll take on real responsibility and gain the hands‑on experience only possible in a high‑growth startup.
• Guaranteed career advancement opportunities in a rapidly growing team
• An ambitious team that feels like family and sees their work as more than just a job
• Real shares in our company with the most favorable tax treatment - no VSOP/ESOP
• Free team dinner (up to 4x/week)
• Urban Sports Club  membership and access to a company bike - join our team workouts 3x/week
• Easy relocation to Munich - our office is located in the Werk1 Startup Incubator
  , where you can rent a 1‑bedroom apartment right next to the office for just €800/month
• Access to any AI or productivity tools you need

Technical

Skills & Experience:

• Proven track record of architecting and building complex,
  AI/LLM‑powered systems or agents in production, including model serving, orchestration of agent workflows, monitoring, and scaling AI workloads
• Designing systems that process and structure large volumes of unstructured data
• Developing evaluation and feedback loops to measure and improve AI system performance
• Experience with Python is required
• Experience in full‑stack development (React / Typescript / FastAPI) is a plus

Mindset & Commitment:

• High agency & ownership
  :
  You develop new ideas and drive them in execution under minimal guidance
• Mission‑driven
  :
  Your job is part of how you define yourself. You are fully committed to your work and achieving ambitious goals amid uncertainty.
• Product mindset
  :
  You demonstrate product thinking on a deep level and solve problems end‑to‑end
• You’re excited to iterate quickly and build software in…