Founding Engineer

About the Role This is a founding engineering role at a seed-stage AI infrastructure company building a production-grade LLM gateway — the backbone layer that helps AI-first teams integrate, route, secure, and optimise across hundreds of large language models. You'll work directly with the founding team to shape both the product and the engineering culture from the ground up. What You'll Do Design and build core backend services within a pragmatic microservices architecture, primarily in Go. Develop and maintain the LLM gateway, including intelligent routing, failover, load balancing, and observability features. Architect scalable systems using Kubernetes, distributed caches, and multiple SQL databases. Collaborate closely with founders to define technical direction and make high-impact product decisions. Evolve and redefine the tech stack as the product and team grow. What We're Looking For 5+ years of backend development experience, with strong hands-on Go (Golang) expertise. Deep understanding of concurrency and experience applying concurrent programming patterns in practice. Proven experience designing and working with microservices architectures and API gateways. Familiarity with a variety of caching strategies and database types, and the judgement to choose between them. Ability to balance architectural rigour with pragmatism — knowing when to build for scale vs. speed. A self-starter mindset: comfortable picking up new technologies independently and thriving in a fast-moving environment. Right to work in the United Kingdom without visa sponsorship. Compensation & Benefits Competitive total compensation package with significant equity . Visa sponsorship is not available for this role. Location On-site in London, United Kingdom .