Senior Backend Engineer - Payin Platform

As a Backend Engineer on the Recurring Payin team, you will help design and maintain the Direct Debit API and the broader Payin platform that powers Wise’s money-movement infrastructure. You will build scalable Java/Kotlin services on AWS, shaping how customers schedule top-ups and authorize automated funding. Your work will impact millions of users by optimising payment routing and reliability across providers. This role combines hands-on backend work with security, reliability, and cross-team collaboration to advance Wise’s mission of borderless money movement.

• Design, develop, test, and maintain backend services in Java/Kotlin with Spring Boot on AWS
• Build and maintain RESTful APIs serving web and mobile platforms
• Develop and optimise services powering card pay-in methods for high transaction scale
• Design and implement PostgreSQL schemas and optimise SQL for high-volume data
• Build and maintain event-driven architectures using Apache Kafka for async processing
• Develop a payment orchestration system routing payments across PSPs for cost/reliability
• Write automated tests (unit, integration, E2E) ensuring financial system correctness
• Conduct code reviews to ensure quality, security, and engineering standards
• Participate in on-call rotations for Tier 2 production incidents
• Collaborate with product managers, designers, analysts, and engineers on cross-functional projects
• Identify and resolve performance bottlenecks, scalability issues, and technical debt
• Ensure security best practices and regulatory compliance when handling financial data

• collaboration
• communication
• problem-solving
• Java
• Kotlin
• Spring Boot