Senior Software Engineer

Senior Software Engineer | Payments Platform

London or Remote

Reports to:

CTO

A high growth UK payments technology company building infrastructure that goes far beyond simple card processing. The platform orchestrates complex money movement across cards, Direct Debit and open banking, handling allocation logic, multi party settlement and reconciliation  mandate is to also build an insights led, AI CFO, supporting businesses on their predictability and forecasting, especially for SMEs that need to make big financial decisions.

This means building software that is resilient, auditable and capable of handling high value, high volume payment flows without failure. Accuracy enables better insights.

This is a senior engineering position with a strong backend focus. You will design and deliver core services that power payment initiation, allocation engines, settlement workflows and ledgering capabilities.

You will work directly with the CTO and a small, high calibre team to shape architecture decisions, improve system performance and ensure production grade reliability as volumes scale.

This is not feature factory work. It is deep systems engineering in a regulated, transaction heavy environment.

• Design and build scalable Java services that underpin payment processing and internal ledger logic
• Develop REST APIs and microservices that manage transaction orchestration, reconciliation and payouts
• Optimise performance and ensure resilience across high throughput systems
• Contribute to architectural decisions as the platform evolves
• Deliver secure, production ready releases
• Own quality through testing, code reviews and proactive production monitoring

• 5+ years commercial software engineering experience with strong Java capability
• Proven delivery using Spring Boot in microservices architectures
• Experience building RESTful APIs in transaction driven environments
• Strong SQL and No
  
  SQL knowledge, ideally Postgre
  
  SQL and MongoDB
• Experience with Docker, CI/CD pipelines and cloud environments such as AWS or GCP
• Comfort operating in systems where reliability and correctness are non negotiable

• Background in payments, fintech or financial transaction systems
• Experience with Kafka or Rabbit
  
  MQ for event driven processing
• Exposure to PCI DSS, encryption standards and secure data handling
• Familiarity with Kubernetes, Terraform or infrastructure automation

• Fully remote or one day a week in London
• Equity with three year vesting
• Direct impact on architecture and product direction

If you are a senior backend engineer who wants to build real payment rails rather than surface level features, this is worth a conversation.