Senior Software Engineer

Overview of the role This role sits in the Banking and FX tribe, which owns payment processing, FX pricing and trading, the ledger, reconciliation, bank integrations, FIX engine connectivity, payment compliance and the client portal. Between them, that covers the movement of client money end to end and everything clients see while it happens. You will be building services in .NET 10 on Azure, mostly asynchronous flows that have to stay correct when a banking partner times out halfway through or when the same message arrives twice. It's an end-to-end banking platform, so the work spans all of it rather than one corner: payments, FX, the ledger, reconciliation, integrations, compliance and the portal. Wherever it lands, getting it right beats getting it out. You make the design calls on your domain and argue them out with the tribe. You build it, you run it, you own it. Services stay with the engineers who wrote them, which means you're trusted to build them your way. The role is hybrid, with 2 to 3 days a week in our London office. Key Responsibilities Design, build and run services in .NET 10 on Azure, owning them from first commit through to production support. Build asynchronous flows that stay correct under partial failure, timeouts, retries and duplicate delivery. Work across the platform: payment processing, FX pricing and trading, the ledger and reconciliation, bank and scheme integrations, FIX connectivity, payment compliance and the client portal. Integrate with banking partners and payment schemes, including the parts of those integrations nobody documents. Make the architectural calls on your domain, write them down, and defend them in front of the tribe. Build in security, availability, reliability and observability from the start, and instrument your services so the answer to what's happening is already in a dashboard. Use AI tooling well. We use Claude Code daily, and we expect judgement about where it earns its place and where it doesn't. Review code, raise the standard around you, and help less experienced engineers get better Skills, Knowledge and Expertise Plenty of .NET behind you, and experience running your own services in production rather than shipping features into someone else's. Production experience on cloud platforms. Azure ideally, but similar experiences on AWS or GCP are just as valuable. Comfort with asynchronous, event-driven systems and the awkward parts that come with them: idempotency, ordering, retries, poison messages, exactly-once as a promise nobody can keep. Security, availability, reliability and observability built in from the start, not bolted on at the end. You think about who can reach what, you know how your service behaves when a dependency disappears, and you instrument it accordingly. We use Grafana and Application Insights. We hold client money, so this is the job rather than a preference. Real experience building software with AI, not just an interest in it. We want someone with a feel for when it helps and when it's quietly making a mess. Strong SQL Server, including query and schema work under real load, and strong familiarity with code-first ORMs, bonus points if its EF Core. Solid testing instincts and the ability to say what a piece of code is actually protected against. Comfortable working somewhere regulated, where changes to how money moves need evidence behind them. Clear communication with engineers and non-engineers, the willingness to disagree, and to commit once the call is made Useful, but not required Payment processing systems Double-entry ledgers FX products and pricing Reconciliation and breaks Payment compliance Bank and scheme integrations FIX protocol and market connectivity If you've done any of it, say so. If you haven't, we'd rather teach you that than compromise on the engineering. Our Development Environment .NET 10, SQL Server and Azure, with the right tool for each job rather than a house framework for everything. Azure DevOps for planning and CI/CD. Grafana and Application Insights for observability. Claude Code in daily use. Autonomous teams, short paths between a decision and it being live Macbook Pros and Jetbrains Rider Benefits We believe great people do their best work when they feel supported, rewarded, and empowered to grow. That’s why we offer a benefits package designed to support your career, wellbeing, finances, and life outside of work. 🌴 Time to Recharge 25 days’ annual leave, plus bank holidays An extra day off for your birthday Holiday loyalty scheme rewarding long-term service Work abroad scheme for added flexibility 💰 Financial Wellbeing Competitive pension scheme via salary exchange Annual discretionary bonus scheme (eligible after probation) Financial education, planning & coaching platform Interest-free Season Ticket Loan for London travel Salary exchange nursery fee scheme 🩺 Health & Wellbeing Life Insurance Healthcare platform including: Cashback on dental, optical & physio Virtual GP access Mental health and stress support helplines Additional wellbeing resources 👶 Family & Lifestyle Support Enhanced parental leave Cycle to work scheme Flexible benefits that support everyday life 🚀 Growth & Career Development Career development and progression tools Opportunities to grow within a fast-scaling international business 🎉 A Great Team Culture From sporting events and pub nights to seasonal celebrations and socials, we make time to connect and celebrate together. Diversity & Inclusion We believe that diversity and inclusion are essential to our success. We are committed to fostering a culture where everyone feels valued and respected, regardless of their background, identity or experiences. By embracing diverse perspectives and promoting equity, we aim to create an environment where all employees can perform and reach their full potential. What’s next? We will review your application and come back to you as soon as possible. You must be eligible to work in the UK to be considered for this position. Full background checks will be carried out on all successful candidates.