Senior Software Engineer

Founding EngineerTech: Python or any modern Backend, Postgres, AWS, LLM APIsOffice: Central London (Hybrid)Salary: Up to £160,000 + meaningful equityEng Size: 10We're working with an early-stage AI company building the "AI for the mid-market"They've secured £10M+ pre-seed investment with strong inbound demand, backed by operators from the leading forces in tech. Already shipping for real customers.They're hiring a Founding Backend Engineer to help build the core platform — the systems that let customers surface, prioritise and govern AI use cases across their business. You'll be one of the first engineering hires, working shoulder-to-shoulder with the founders, with outsized influence over architecture, stack and how the engineering team is built out from here.What you'll do:Design and build the backend systems powering the core product — APIs, data models, integrations and the infrastructure connecting to LLM providersOwn architecture decisions early, with no legacy to work around and real say in the stack going forwardShip fast and directly to real customers, using the in-house MSP testbed and early client relationships to validate what you buildWork hands-on across the stack where needed — this is a small team, so scope stretches beyond "backend only" some weeksHelp set engineering standards and practices (testing, code review, CI/CD) that the team will scale withContribute to early technical hiring as the team growsWhat they need:Strong production experience building backend systems in Python / any modern backendComfortable owning things end-to-end — API design, data modelling, deployment, monitoringSome experience integrating with or building on top of LLM APIs (OpenAI, Anthropic, etc.)Startup or 0-to-1 mentality — genuinely energised by ambiguity and building from scratchStrong product instincts — cares about what's being built, not just howComfortable being in-office with a small, high-intensity founding teamBonus: previous founding engineer experience, leadership, ex-founder / ex-CTO, exposure to AI/agent tooling, or a track record of shipping fast at an early-stage startup.