Backend Software Engineer, Golang - London
Reflexivity · London, England, United Kingdom · £80K–£160K/yr
Financial Services · 11-50 employees
About the role
You will build and maintain Golang services that power core product workflows and design APIs for AI-driven investment systems. You are also responsible for improving system performance, reliability, and observability while collaborating with product teams.
What they look for
Requirements
The role requires 5+ years of backend engineering experience with strong proficiency in Golang and experience in data-heavy systems. Candidates should have a background in startups and exposure to the fintech or investment domain.
Benefits
Full description
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
