Senior Backend Engineer - Payin Platform

Recurring Payin team owns the Direct Debit API that powers automated payments into Wise. Underneath this, we are building a platform that allows customers to easily schedule top-ups or business collections. The platform is also built on top of our internal Payin Platform rails; which is a critical component to the Wise money-movement machine and we’re looking for an engineer motivated to come and help us build for this. We primarily offer APIs for any partner looking to set up automated funding or pre-authorizations. From setting up GBP balance top ups automatically to allowing business partners collect EUR bills monthly without having the customer go through the flow every time; our platform aims to consolidate all these use-cases.

We aim to allow customers to give a one time permission (pre-authorization) for Wise to pull money across any payment method, a USD bank account or a EUR issued bank card; you name it. Job

Responsibilities

• Design, develop, test, and maintain backend services written in Java and Kotlin using the Spring Boot framework, deployed on cloud infrastructure (AWS)
• Build and maintain RESTful APIs that serve millions of customers across web and mobile platforms
• Develop and optimise services powering the card pay-in payment method — one of the most popular payment methods, enabling Wise customers to move around £1 billion every month
• Design and implement database schemas, write and optimise SQL queries against PostgreSQL databases handling high-volume transactional data
• Build and maintain event-driven architectures using Apache Kafka for asynchronous processing of financial events across distributed services
• Develop and maintain a payment orchestration system that dynamically routes payments across Payment Service Providers to optimize for cost and reliability
• Write automated tests (unit, integration, and end-to-end) to ensure correctness and reliability of financial systems
• Conduct code reviews for team members, ensuring code quality, security, and adherence to engineering standards
• Participate in on-call rotations to monitor and respond to production incidents for Tier 2 critical services
• Collaborate with product managers, designers, analysts, and engineers across other teams to deliver cross-functional projects
• Identify and resolve performance bottlenecks, scalability issues, and technical debt in existing systems
• Ensure development follows security best practices, particularly around handling of sensitive financial data and compliance with financial regulations