Principal Software Engineer

Principal Software Engineer – Cards & Credit (Python, Java, Clojure, AWS) Up to £135,000 bonus (15-22%) annual equity ️ Python, Distributed Systems, High-Scale Architecture London, hybrid working (2 days/week) Leading business lending platform I'm partnered with one of the UK’s most successful fintech scale-ups who have built a platform helping businesses access more than £15 billion in funding. They’ve recently launched a new product line which has become the company’s highest-growth area, with its own dedicated leadership and roadmap. They’re now hiring a Principal Engineer to become the technical lead across two core engineering teams working in the card and credit space. This is a critical hands-on IC role driving architecture, mentoring senior engineers, and setting the engineering direction for one of the most commercially important product areas in the business. What you’ll be doing Be the senior technical authority across two product teams focused on credit and card systems Lead architectural decisions for a high-volume, low-latency backend platform Work closely with senior product, platform and engineering stakeholders to define technical direction Mentor Lead and Senior Engineers, driving engineering excellence and fostering a high-performance culture Play a key role in the migration from legacy technologies to a fully Python-based modern stack Bring much-needed domain expertise in cards and credit to a high-growth area with a greenfield mindset What they’re looking for Strong engineering background with deep experience in backend systems (Python preferred, Ruby/Java/Clojure/Go also considered) Experience working on card-based products — ideally credit, but debit or prepaid also considered Strong architectural and system design skills What’s in it for you Bonus at approximately 15% (with potential to earn up to 22%) Annual stock grant Dedicated annual learning budget Private medical and dental insurance Broad range of benefits including enhanced Paternity/Maternity cover Hybrid working – 2 days/week in their London office (no fixed days) Be part of a high-ownership role with real scope to shape the success of a growing product Principal Software Engineer – Cards & Credit (Python, Java, Clojure, AWS)