Back End Developer Engineer

Senior / Staff Backend Engineer £136k–£180k + equity | Remote Europe or London I'm working with a Series A developer infrastructure startup on one of the more technically demanding backend roles I've come across this year. The platform runs AI agents and background workflows in production, at massive scale. There are no engineering managers. Engineers own large parts of the system and work directly with the founders on architecture. Scaling the infrastructure that executes millions to billions of AI agent workflows per month Building secure execution environments for user-generated code (Firecracker micro-VMs) Server lifecycle management — spinning capacity up and down rapidly under load TypeScript (99% of the codebase) PostgreSQL, Redis, ClickHouse Go emerging as a second language — experience is a bonus but not required Backend engineers who've operated systems at serious scale — fintech, devtools, or infrastructure-heavy SaaS Engineers who use AI tooling heavily — this is screened for directly in the interview Full-stack engineers whose instinct is to reach for the frontend Anyone who needs structured management to ship