Senior Software Engineer | Payments Platform
London or Remote
Reports to: CTO
The Business
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 at scale. The 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.
The Role
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.
Key Responsibilities
* 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
Core Experience
* 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 NoSQL knowledge, ideally PostgreSQL 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
Highly Relevant
* Background in payments, fintech or financial transaction systems
* Experience with Kafka or RabbitMQ for event driven processing
* Exposure to PCI DSS, encryption standards and secure data handling
* Familiarity with Kubernetes, Terraform or infrastructure automation
What You Get
* Competitive base salary
* Fully remote or one day a week in London
* Equity with three year vesting
* Direct impact on architecture and product direction
* A serious engineering challenge in modern payments infrastructure
If you are a senior backend engineer who wants to build real payment rails rather than surface level features, this is worth a conversation.