Principal Engineer (Java) – Payments – up to £110k

About the role

We are seeking a Principal Engineer with deep Java expertise (Java 17/21) and extensive payments product experience to shape real‑time payment solutions across Faster Payments, Real‑Time Payments, card schemes, BACS, mobile wallets and APIs. The role is hands‑on (≈80%) with a strategic architectural component (≈20%) and will be based in London, Chatham (Kent) or Wolverhampton, working onsite two days a week.

Key responsibilities

• Lead the design and implementation of a modern, cloud‑native foundation and data platform that is secure, scalable and fully automated.
• Build high‑performance, secure RESTful and GraphQL APIs that integrate with core banking systems such as Mambu and Open Banking platforms.
• Collaborate with data teams to create robust pipelines using Apache Kafka, Snowflake or Databricks.
• Implement observability and monitoring solutions with Prometheus, Grafana or Datadog to detect and resolve performance bottlenecks.
• Analyse and optimise existing systems for better performance, scalability and maintainability.

Required profile

• Proven experience building and scaling banking payment systems (Faster Payments, Real‑Time Payments, card, BACS, mobile wallets, APIs).
• Demonstrated ability to lead architectural challenges and guide engineering teams.
• Hands‑on development background in Java, with additional experience in C#, Python or React.
• Strong understanding of core banking platforms (e.g., Mambu), cloud‑native microservices and DevOps practices.
• Knowledge of regulatory and compliance standards such as PSD2, PCI DSS and GDPR.

Required skills

• Java 17/21
• C#
• Python
• React
• Cloud‑native architectures
• Microservices
• DevOps
• RESTful APIs
• GraphQL
• Mambu
• Apache Kafka
• Snowflake
• Databricks
• Prometheus
• Grafana
• Datadog
• PSD2
• PCI DSS
• GDPR

What we offer

• Basic salary up to £110,000 per year
• 25% performance‑based bonus
• Comprehensive benefits package
• Hybrid working model (2 days onsite)