Senior AI Engineer

The AI Operating System for Private Capital.

Capsa AI

Private capital funds have to find potential investments, research and analyse them thoroughly, monitor them over time, drive improvements, and decide when to buy and sell. They’ve got to see through the marketing. They’ve got to outbid the competition. And they’ve got to learn from every deal they do. Historically, these processes have run on people, we are building the AI Operating System that will run them in the future.

We’re focused, ambitious, and obsessed with building a category-defining company. In the last 12 months we’ve grown ARR 15x, achieved product–market fit with leading multi‑billion‑dollar PE firms, and expanded across the US, UK, and Europe. Now we’re doubling down: we’ve raised a large Series A from top‑tier VC investors to scale the team. We’re hiring hyper‑talented people who want to work at the forefront of AI and revolutionise an industry.

• Role: Senior AI Engineer
• Location: London, UK (Hybrid, in‑person 4 days per week)
• Team
  :
  Engineering
• Compensation: Top of market. Competitive base + OTE

Take what you already know about AI systems, or about building at the frontier, into a category-defining company. A fast track to owning the infrastructure that powers decisions at the world's largest PE firms.

You’ll design and ship the core AI capabilities that sit at the heart of our platform, working directly alongside our founding engineers and CTO. Whether you’ve built production LLM systems, designed agentic architectures, or pushed the limits of RAG and reasoning chains, you bring depth most engineers don’t have, and the job is to point that depth at problems the industry has never had good tooling for.

This isn’t a place to maintain someone else’s codebase. We hire engineers who want to own things end-to-end from day one, and we give responsibility based on impact, not seniority. Strong execution is the fast track to shaping the technical direction of a high‑growth AI company, building alongside a founding team that will back your best ideas.

• Build the agent’s brain. Design and ship features that give our AI genuine investment expertise, the kind that makes analysts faster and makes partners take notice.
• Push the architecture forward. Prompts, reasoning chains, agent design. You own the quality and reliability of what the model produces, not just the code that runs it.
• Stay at the frontier. Evaluate new models, techniques, and research as they drop. When something better exists, you’re the one who brings it in.
• Expand what the agent can see. Integrate new data sources into the loop and increase the depth and breadth of analysis the platform can perform.
• Keep the codebase clean. Uphold rigorous standards across everything you ship. Tech debt is a tax on velocity, and you don’t let it accumulate.

• Agentic assistant with a finance-focused toolkit and advanced document authoring features
• Scalable document ingestion and indexing pipeline
• In‑house, streaming‑first agent framework
• AI-assisted document editor

• Engineering depth, not just exposure. Four or more years building production software, with meaningful time spent on AI/ML systems at a venture‑backed startup or top tech firm
  -not as a side project, as the core of the work.
• You’ve shipped things that mattered. Entire features or products taken from ideation to production, with impact you can speak to. If you can’t point to what changed because of your work, that’s a flag.
• The right technical toolkit. Strong Python, hands‑on experience with LLMs (OpenAI, Anthropic, open‑source), agent frameworks, RAG pipelines, vector databases, and backend infrastructure like FastAPI, Postgres, and Elastic Search, or close enough that the gaps close fast.
• Domain curiosity, not just technical ability. You go deep on the problem, not just the implementation. You care about what the product does for the person using it, and that shows in how you build.
• Comfortable at pace. Fast-moving environments are where you do your best work, not something you tolerate.

• Low ego, high ownership. You want to be part of building something that…