Backend Engineer (JVM)

Series-a Fintech
Charing Cross, United Kingdom
4 days ago

Role details

Contract type
Permanent contract
Employment type
Full-time (> 32 hours)
Working hours
Regular working hours
Languages
English
Experience level
Senior
Compensation
£ 110K

Job location

Charing Cross, United Kingdom

Tech stack

Java
API
Artificial Intelligence
C++
Distributed Systems
Fault Tolerance
Python
Scala
Unstructured Data
Rust
Large Language Models
Backend
Kotlin
Information Technology

Requirements

Tech: Kotlin (open to any JVM background), Python, Terraform, Agentic AI, cloud-native, event-driven services

If you've built fault-tolerant, distributed systems before, tools matter less than judgement

You'll Have

  • 5+ years building production distributed systems in a startup environment, using backend languages like Java, Kotlin, Scala, Python, C++, Rust or Go
  • Experience designing external-facing APIs and working with messy, unstructured data
  • Shipped AI/ LLM systems beyond proof-of-concept
  • Startup experience: comfortable in ambiguity, taken high ownership
  • FinTech product experience
  • Strong instincts on trade-offs, speed vs correctness
  • Computer Science degree or equivalent

Benefits & conditions

£80,000 - £110,000 + Equity + Benefits

Did you know financial fraud costs the UK economy £200bn+ per year, accounting for over 40% of crime in England and Wales? This early-stage FinTech is on a mission to fight financial crime and reduce scams in online payments

High-ownership, mission-driven, working with sensitive financial data. This is critical infrastructure. When it fails, real people lose money.

What You'll Do

  • Build the APIs and UIs banks plug into their payment flows
  • Connect the investigation engine to messy, real-world data (APIs, documents, scraped sources - most of it unstructured)
  • Design the orchestration layer that gathers and evaluates evidence across heterogeneous systems
  • Ship reliable, secure, observable production code
  • Deploy and iterate on LLM-powered investigation flows (not just prototypes)
  • Make smart build vs buy decisions and own the trade-offs

This isn't a feature factory. You'll design, build, ship, own., Why Join?

  • Work with a highly talented team of 8 other Engineers
  • Real equity
  • High-stakes technical challenges
  • AI X distributed systems X regulated finance

Apply for this position