Staff Software Engineer - Payments | London | Up to £250k Base + Equity
About the Company
We're partnered with a fast-growing fintech building the next generation of financial infrastructure.
The platform sits directly in the flow of real money movement, powering payment processing, risk decisions, reconciliation, compliance workflows, and transaction orchestration at scale. These are business-critical systems where correctness, reliability, and resilience matter just as much as performance.
The engineering organisation is intentionally small, highly experienced, and operates with a high degree of autonomy. Engineers are trusted to make decisions, own systems end-to-end, and have direct influence over both architecture and product outcomes.
The Opportunity
This is a Staff-level engineering role focused on designing and operating the core systems that power payments across the platform.
You'll work on complex distributed systems challenges involving consistency, fault tolerance, idempotency, reconciliation, and auditability, helping ensure critical financial infrastructure remains accurate and reliable under scale, failure, and regulatory scrutiny.
Working closely with Product, Compliance, Operations, and Engineering, you'll play a key role in shaping both the technical direction of the platform and the systems that move money every day.
What You'll Be Doing
- Design and build high-volume payment orchestration services
- Develop real-time risk and decisioning systems operating directly within payment flows
- Own ledgering and reconciliation systems that serve as the financial source of truth
- Build fault-tolerant, event-driven architectures capable of operating reliably under failure conditions
- Design systems with a strong focus on consistency, resilience, idempotency, and auditability
- Improve observability, monitoring, tracing, and operational tooling across critical services
- Partner with Compliance and Operations teams to build verification, screening, and audit-ready workflows
- Influence technical architecture and engineering standards across the organisation
- Own services throughout their entire lifecycle, from design and implementation through production operation
What They're Looking For
Core Requirements
- Strong backend and distributed systems engineering experience
- Proven track record building production systems where correctness and reliability are critical
- Background in payments, fintech, banking, financial infrastructure, transaction processing, trading systems, or similarly complex domains
- Deep understanding of distributed systems concepts including consistency, fault tolerance, scalability, idempotency, and event-driven architectures
- Experience operating high-availability production environments
- Strong database and data architecture fundamentals
- Ability to independently own and deliver complex technical initiatives
- Comfortable collaborating with both technical and non-technical stakeholders
Technology
The engineering team primarily works in Rust, but they are open to exceptional engineers from:
- Rust
- Go
- C++
Strong engineering fundamentals and systems thinking are valued significantly more than direct Rust experience.
Nice to Have
- Payments infrastructure
- Ledgering and reconciliation systems
- Fraud, risk, or decisioning platforms
- Compliance, KYC, AML, or audit systems
- Crypto or digital asset infrastructure
- High-performance or low-latency distributed systems
- Strong observability and operational excellence experience
Why Join?
- Build critical financial infrastructure from the ground up
- Work on systems responsible for moving real money
- High ownership and autonomy from day one
- Small team of exceptionally strong engineers
- Challenging distributed systems problems at scale
- Product-focused engineering culture
- Significant architectural influence and technical ownership
Compensation
- Up to £250,000 Base Salary
- Meaningful Equity Package
- Competitive Total Compensation