Backend Software Engineer, Golang - London

You build backend systems that stay up when things get ugly. You care about correctness, performance, and clarity over cleverness. You want your code to power decisions involving real money. If you have only worked on internal tools or low-impact services, this is not the role.

The Role, In Plain English

You will build the backend systems that power Reflexivity’s AI-driven investment platform. This role exists because scale, data complexity, and latency matter deeply in finance. You will work closely with AI and product teams to ship production-grade systems.

What You’ll Be Responsible For

Build and maintain Golang services that power core product workflows

Design APIs and data pipelines used by AI and reasoning systems

Improve system performance, reliability, and observability

Review and challenge designs to keep systems simple and scalable

Debug production issues with speed and discipline

What “Good” Looks Like in This Role

After 3 months: You ship production code confidently and understand system trade-offs.

After 6 months: You own critical services and improve their performance or reliability.

After 12 months: You influence architecture decisions and mentor other engineers.

Who You Are (Must-Haves)

5 plus years backend engineering experience

Strong Golang experience in production systems

Startup experience on a core product

Experience working with data-heavy systems

Comfortable using AI-assisted coding tools daily

Fintech or investment domain exposure

Nice-to-Haves

Experience supporting ML or LLM systems

Distributed systems or low-latency data pipelines

How We Work

Engineers own systems end to end

Clear accountability and direct feedback

In-office team with high trust and high ownership

Why This Role Is Worth Your Time

Work on systems that directly affect investor outcomes

Strong technical ownership

High bar engineering culture without bureaucracy

Compensation & Practicalities

£80,000 to £160,000 depending on experience

Equity included

In-office role based in London

No agencies

Salary Range

£80,000 — £160,000 GBP