Staff Payment Gateway Backend Infrastructure Engineer — Hybrid, London, United Kingdom

Overview

Set technical direction for distributed gateway, routing and payout infrastructure, spanning merchant requests, acquirer selection and payment or payout rails. Lead high-throughput, low-latency architecture and operational resilience while keeping production transactions consistent and auditable.

Requirements

• Significant hands-on experience designing, building and operating large-scale distributed backend systems, with technical leadership across multiple teams.
• Demonstrated architecture work for high-throughput, low-latency critical services.
• Deep understanding of idempotency, retries and backoff, circuit breakers, queueing, backpressure, consistency, failure domains and recovery.
• Strong proficiency in .NET or Java with clear maintainable production code.
• Experience with event-driven or streaming architectures and relational and non-relational data stores at scale.
• Hands-on cloud development, containers, orchestration and infrastructure as code; AWS and Azure are technologies used by the source.
• Experience owning on-call production systems, monitoring, observability and incident response.
• Experience leading complex migrations or re-architecture of live critical services with no loss of availability or integrity.
• Ability to write design documents and influence engineering and nontechnical stakeholders.
• Prior payment or highly regulated correctness-critical systems, multi-region active-active architecture and mentoring engineers toward staff level are advantageous, not mandatory.

Responsibilities

• Own gateway, routing and payout architecture across high-throughput services.
• Define service boundaries, data models, availability and latency budgets and recovery objectives.
• Design resilience, failover, idempotency and graceful degradation for partial failures.
• Lead technical design, rollout and migrations across multiple teams.
• Improve observability, capacity planning, load testing, incident response and root-cause remediation.
• Conduct architecture and code reviews and mentor senior engineers.
• Coordinate phased delivery and build-versus-buy decisions with engineering and product stakeholders.

Conditions

• Full-time hybrid position in London, United Kingdom, with three days per week in the office.