Principal Engineer (Payments)

About Us_ // At Masabi , we’re driving the fare payment revolution, powering the journeys of millions all over the world. We build fare collection platforms that allow riders to seamlessly buy and present tickets for public transport either on their mobile phones, from a ticket machine, or even by tapping their bank card to travel. Our Justride platform is used in over 250 locations globally, including some of the largest cities in the world. With our industry-first mobile ticketing SDK, we’ve partnered with large players in the transport space, including Uber, Moovit and Transit. Your own journey is important to us too. Choosing a role here means joining a network of innovators from all walks of life; a group of passionate individuals who consistently deliver. Here, you’ll find the tools you need to build the career you want. Whether you’re taking the direct route or trying a new path, we’ll support you no matter what. The Role_ // We’re looking for a Principal Engineer - Payments to join Masabi’s Architecture team, with a primary focus on our payments domain. This is a senior role for someone who combines strong technical judgement with deep payments experience. You’ll shape the technical direction of our payments platform while staying close enough to the detail to design, review and support meaningful technical work. Working across the engineering organisation, you’ll act as a senior technical leader within the payments domain: contributing to architecture, guiding complex decisions and helping teams build scalable, resilient systems that support millions of journeys worldwide. The role suits someone who can move between system-level thinking and implementation, who understands trade-offs, can navigate ambiguity and helps turn complex or loosely defined problems into clear, practical technical approaches. Location_ // This role is open to candidates based anywhere in the UK, with the flexibility to work fully remotely. For those based in or around London, we also offer the option of hybrid working from our London office. Responsibilities_ • Shape the technical direction of Masabi’s payments platform, contributing to architecture, standards and engineering best practices • Design and deliver scalable, secure, resilient and cost-effective payment solutions aligned with Masabi’s platform direction • Support teams in building towards a modern, microservices-based architecture while balancing delivery priorities and long-term platform health • Stay close to technical delivery through architecture reviews, design discussions and targeted hands-on contribution where needed • Identify and work through complex technical challenges related to scalability, resilience, operational performance and system evolution • Act as a senior technical advisor across engineering teams, supporting and influencing technical decisions, particularly within the payments domain • Work with external providers and payment partners on integrations, technical alignment and problem-solving • Contribute to technical roadmap planning, prioritisation, technical scoping and architecture discussions for complex initiatives • Produce clear technical documentation and contribute to engineering standards, technical forums and good practices across the organisation About You_ // You bring a mix of strong technical expertise, sound judgement and real-world payments experience. • Strong experience working on payment systems, including integrations with PSPs, gateways, EMV, contactless EMV, acquirers, etc. • Good understanding of payment flows, transaction lifecycles and system design considerations • Experience designing and evolving distributed systems and microservices architectures • You’ve operated at Principal or Staff level, shaping technica