Software Engineer
- Level
- Mid
- Apply from
- United Kingdom
About the role
- Build and operate production backend systems.
- Fluency in backend languages like Ruby on Rails.
- Experience with microservice architecture.
- Focus on quality and detail in code.
- Collaborative environment with ownership mentality.
Skills the posting asks for
- Ruby on Rails
- JavaScript
- NestJS
- Python
- FastAPI
Summarised from the employer’s posting, which is reproduced in full below.
The employer’s full posting
About Letly
Letly is the AI-Native operating company built for the home. We believe the home should be autonomously run and we're building the software that will run all rental properties end-to-end.
The backend at Letly is technically difficult on purpose as the operational realities of handling property and money are messy. But the foundations are already there: 10+ backend and AI services, a monorepo on the frontend, GitOps and Kubernetes on the infra side. You'd be building on solid ground rather than firefighting a fragile prototype — with a lot still to build.
We've raised a $4m pre-seed and are a small, high-agency, engineering-oriented team, growing revenue at >100% month-over-month. We're hiring to facilitate this aggressive growth.
Our stack
Small, well-factored services with clear boundaries. Tests are written alongside the code, not after it — they're what lets us move quickly without breaking things that handle money. Trunk-based CI/CD: you ship to production and own it, with observability and clean rollbacks. Lean frameworks, readable code.
We work on a wide spectrum of technical challenges from money movement to operational logistics (scheduling, bookings, access) mediated over event-driven systems, to building around AI agents in production that are capable of executing autonomously under the hood.
What We're Looking For
We aim to complete end-to-end in under a week.
On top of base salary, equity and annual bonus, you're also entitled to:
Letly is the AI-Native operating company built for the home. We believe the home should be autonomously run and we're building the software that will run all rental properties end-to-end.
The backend at Letly is technically difficult on purpose as the operational realities of handling property and money are messy. But the foundations are already there: 10+ backend and AI services, a monorepo on the frontend, GitOps and Kubernetes on the infra side. You'd be building on solid ground rather than firefighting a fragile prototype — with a lot still to build.
We've raised a $4m pre-seed and are a small, high-agency, engineering-oriented team, growing revenue at >100% month-over-month. We're hiring to facilitate this aggressive growth.
Our stack
- Backend — a microservice architecture in NestJS and TypeScript, with Python and FastAPI for the AI agent services.
- Data — MongoDB Atlas and Redis.
- Event-driven — services coordinate over Pub/Sub rather than calling each other directly.
- Infra — Kubernetes on GCP (GKE), deployed via ArgoCD.
- Frontend — Angular in an Nx monorepo.
Small, well-factored services with clear boundaries. Tests are written alongside the code, not after it — they're what lets us move quickly without breaking things that handle money. Trunk-based CI/CD: you ship to production and own it, with observability and clean rollbacks. Lean frameworks, readable code.
We work on a wide spectrum of technical challenges from money movement to operational logistics (scheduling, bookings, access) mediated over event-driven systems, to building around AI agents in production that are capable of executing autonomously under the hood.
What We're Looking For
- You've built and operated production backend systems that real users depended on. We care about the scope you've owned and how you owned it.
- First Class or high 2:1 (or international equivalent) in Computer Science or a relevant technical field.
- Fluency in at least one backend language and framework. You don't need to arrive fluent in our stack: we hire engineers who've built production systems with any robust framework — NestJS/TypeScript, Java/Spring Boot, Go, Kotlin, C#/.NET or Ruby on Rails — and can ramp into TypeScript fast.
- System design: where a service boundary belongs, what a design trades away, how services coordinate — events, queues, retries that are safe to repeat — and how it holds up once it's live.
- Fundamentals: concurrency, HTTP and API design, auth, data modelling and transactions (document or relational), changing a live schema safely, and what happens when a call fails.
- Tests: you treat tests as part of shipping, you work comfortably in a shared trunk, and you can quickly understand a large codebase you didn't write.
- You use AI heavily and still know exactly what you shipped. Generated code has the same quality bar as what you wrote by hand: you can explain every line, you've thought about the constraints it has to bear, and you don't merge anything you couldn't have written yourself.
- Hyper-focus on detail. These systems move money and manage assets; we have low tolerance for "mostly right".
- First-principles reasoning. You take a hard problem apart rather than reaching for the nearest familiar pattern.
- Communication clarity. You can explain a complex trade-off to another engineer, and to someone who doesn't write software — because here you'll have to do both.
- Ownership mentality. You own the outcome, not the ticket: start to production, without being chased.
- Collaborative. Teams change the world, not individuals. You make the next engineer better and faster.
- Adaptability. You do well in a fast-moving environment where requirements shift under you.
- Learning velocity. You pick up new paradigms quickly and don't need long to get productive in unfamiliar territory.
- Quality-obsessed. Not just the code — the tests, the docs, the handover, the thing you leave behind.
We aim to complete end-to-end in under a week.
- Screening — 30 minutes with the CEO
- Skills — 45 minutes with the CEO & CTO
- Problem solving — 60 minutes with the CTO
- Slope — 45 minutes with the CEO
- Offer — references and a decision in days
On top of base salary, equity and annual bonus, you're also entitled to:
- Private health insurance
- Paid gym membership
- Three meals a day, in office
- Ubers home on late nights