Principal Software Engineer (City of London)

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)