About the job

A well-funded early-stage AI infrastructure startup is seeking a high-ownership, deeply technical Founding Software Engineer to help build the core AI systems powering the next generation of real-world innovation. The role requires shipping production-grade code from day one, owning full-stack feature development across infrastructure, tooling, and applications, and solving complex technical and operational problems such as scaling infrastructure, fine-tuning models, and collaborating directly with customers and teammates. Candidates should have at least 2+ years of experience building and deploying real products, a strong understanding of LLMs, multimodal models, agents, and tooling (e.g., LangChain, RAG, SFT/RL fine-tuning), as well as expertise in cloud infrastructure, containerization, and relational/graph databases. The role offers a competitive salary of £100k–£180k with meaningful equity, visa sponsorship, relocation support, and the opportunity to work in a high-trust, fast-paced startup environment shaping category-defining AI infrastructure.