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. Some customers execute hundreds of millions of jobs per month. The team is ~13 people. There are no engineering managers. Engineers own large parts of the system and work directly with the founders on architecture.
The core challenge right now is infrastructure scale. Execution volume is growing faster than the team can build, which means the next hires are walking into a genuine distributed systems problem, not a greenfield rebuild or a dashboard feature.
What you'll be working on
* Scaling the infrastructure that executes millions to billions of AI agent workflows per month
* Designing and operating reliable systems under extreme concurrency and rapid load spikes
* Building secure execution environments for user-generated code (Firecracker micro-VMs)
* Server lifecycle management — spinning capacity up and down rapidly under load
* Observability and reliability tooling across the platform
The stack
* TypeScript (99% of the codebase)
* PostgreSQL, Redis, ClickHouse
* Go emerging as a second language — experience is a bonus but not required
* Kubernetes background useful (they're evolving away from it, but the mindset matters)
What they're looking for
* Backend engineers who've operated systems at serious scale — fintech, devtools, or infrastructure-heavy SaaS
* Deep understanding of distributed systems, reliability, and infrastructure design
* Comfortable owning large surface areas with minimal direction
* Engineers who use AI tooling heavily — this is screened for directly in the interview
* High intrinsic motivation — the team moves fast and doesn't slow down for anyone
What they're not looking for
* Full-stack engineers whose instinct is to reach for the frontend
* Anyone who needs structured management to ship
* Candidates coming from large enterprises or low-velocity environments
Comp
* Senior: £136k–£150k + ~0.3% equity
* Staff: £164k–£180k + ~0.3% equity
* Paid trial day as part of the process (£400)
The bar is high. The trial day has roughly a 10% pass rate. But if you've built backend systems at scale and you're the kind of engineer who finds that motivating rather than off-putting — drop me a message.