Founding Engineer (+ Equity) at cepter

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Founding Engineer

Not Disclosed + Equity

cepter is a London-based AI infrastructure startup building the platform to unlock proprietary energy sector data for the AI era. Founded by Kaspar (ex-BCG/terralayr) and Duxi (ex-IBM/ETH Zurich), they are transforming complex technical reports and legal contracts into machine-ready data to accelerate the global energy transition.

As the first engineering hire at cepter, you will architect the systems turning complex energy documents into actionable AI data. You'll build end-to-end features using FastAPI, React, and Temporal, owning everything from database migrations to LLM pipelines. This high-intensity role offers the chance to define the technical foundation for the energy transition's AI infrastructure.

London, UK

• Shape a company from day one as the first engineer, working directly with founders from Oxford, BCG, and ETH Zurich to define the product architecture and culture.
• Solve critical data bottlenecks in the energy transition by building sophisticated AI pipelines that process high-stakes proprietary documents and complex legal technicalities.
• Join a high-performance, high-intensity culture designed for rapid shipping, utilizing cutting-edge tools like Temporal for workflow orchestration and AI-native development workflows with Cursor and Claude.

• Ship end-to-end features across a FastAPI and React/Type Script stack, designing durable domain APIs and data models that work in production-like PR previews.
• Build and debug complex Temporal workflows for long-running AI pipelines, ensuring idempotency, retries, and reliable structured extraction from unstructured documents.
• Own the entire infrastructure and Dev Ops lifecycle using Docker Compose and Railway, while improving developer experience through robust CI checks and observability.

• Brings at least 6 years of experience at high-performance tech startups with a proven track record of shipping full-stack products from scratch.
• Demonstrates deep expertise in Python/FastAPI, Type Script/React, and building production-grade LLM/document pipelines using tools like Langfuse for quality diagnosis.
• Possesses a "founding bar" mindset: high agency in ambiguity, a bias toward small and correct changes, and comfort pairing with AI coding agents to accelerate delivery.

Ok, I'll go first. I'm Jack, an AI that gets to know you on a quick call, learning what you're great at and what you want from your career. Then I help you land your dream job by finding unmissable opportunities as they come up, supporting you with applications, interview prep, and moral support.

And I'm Jill, an AI Recruiter who talks to companies to understand who they're looking to hire. Then I recruit from Jack's network, making an introduction when I spot an excellent candidate.

• Jack's an AI agent for job searching and career coaching. He works for you.
• Jill is the AI recruiter working for the company. She recruits from Jack's network.
• If it's a match and the company wants to meet you, they'll make the intro. In the meantime, if you'd like, Jack will send you excellent alternatives.

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