Senior Full Stack Engineer

Thought Machine's mission is bold – to properly and permanently rid the world's banks of legacy technology. To achieve this, we have developed the foundations of modern banking through core and payments technology which run natively in the cloud. What we are attempting is hard and means we need great people working together to build great technology. We have grown rapidly in the past few years – growing our team to more than 550 individuals across offices in London, New York, Singapore, Sydney and our newly established Engineering Hub in Lisbon. We have raised more than £500m in funding and our investors include Molten Ventures, Eurazeo, Intesa Sanpaolo, Temasek, Nyca Partners, JPMorgan Chase Strategic Investments, Standard Chartered Ventures, and more. We have created a culture that enables our team to produce the best work in the industry while ensuring we have fun along the way. We're regularly cited as having a fantastic workplace culture and have been recognised by Sifted magazine as having one of the highest Glassdoor ratings for a UK fintech company and the industry's most generous employee share package. Named one of the world's most innovative fintechs by Global Finance Magazine, we were also recognised by the Financial Times as one of Europe's fastest-growing companies for two consecutive years—and a UK Best Employer for 2026. This is a full-time, permanent position based in our Lisbon office, requiring four days a week onsite. Software Engineering is a key role within Thought Machine. As an engineering-focused company, we take pride in our engineering excellence, adopting best practices, and utilising modern technologies. Thought Machine software engineers work across the stack to solve complex engineering problems that have not been solved before. As a result, while development at Thought Machine is fast-paced, you will be expected to develop code to the highest standards that scales, is secure, performant, and provides a great user experience. Software Engineers will take complete ownership of a requirement, converting it into an engineering design, task breakdown, and implementation. You’ll be responsible for building both backend services and frontend experiences. Our clients range from the world’s largest financial institutions to smaller regional banks. Our systems must cater to each of these use cases, so we care deeply about providing the ability to configure and customise the user experience based on the client's or end user's persona. Software engineers are expected to bridge the gap between back-end and front-end, crafting delightful experiences that delight all our clients. Duties - Design and implement end-to-end features across the stack, including web applications and backend services. - Ensure your solutions are delivered with security, performance, scale, and user experience in mind. - Write automated unit, integration, acceptance tests, etc. - Interface with other engineering teams to ensure…