Senior Software Engineer

Senior Software Engineer | London (hybrid) | £85k - £99k + Equity | Python | FastAPI | SaaS

Location:

London (hybrid)

• Backend:
  Python (FastAPI), experience in any strongly typed language is required
• Frontend:
  Type Script (Vue.js)
• Cloud Systems: experience across any GCP, Azure, AWS

Are you a Senior Backend Engineer who wants to own the backend properly, not babysit it?

We are working with a fast growing AI startup that is already live with enterprise customers, real revenue, and real technical complexity. The platform is multi-tenant, data heavy, and deeply tied to AI powered workflows.

You will take ownership of the backend platform and set the technical direction. This is a hands on senior role with genuine authority. You will write production code, make architectural decisions, and raise the bar for backend quality across the team.

• Owning backend architecture, performance and reliability across a multi tenant SaaS platform
• Designing and evolving APIs, data models and integrations
• Making pragmatic trade offs around scale, correctness and maintainability
• Setting standards for backend quality, testing and observability
• Working closely with product and frontend engineers to ship end to end features
• Acting as the go to person for backend decisions

• A genuine senior backend engineer with ownership mindset
• Strong experience building and running production backend systems
• Deep API and service design experience in Python or another strong backend language
• Comfort making architectural decisions without over engineering

The ideal candidate is someone who takes ownership naturally and communicates with intent. They are comfortable being the point of accountability for backend decisions and can explain complex technical trade offs clearly to both technical and non technical stakeholders.

We are looking for someone who enjoys working collaboratively, challenges ideas constructively, and knows when to push back and when to align. They are calm under pressure, methodical when things break, and thoughtful about the impact their decisions have on users, teammates, and the wider system. They care about code quality, but they care more about building reliable software that works in the real world.

If you're interested, drop me an email at  We're arranging interviews within the next 2 weeks.