Principal C# Developer .Net AWS - FinTech

Role overview A senior hands-on engineering position sits at the core of a growing financial technology organisation that is building highly performant, scalable services on a modern Microsoft technology stack. The role partners with cross-functional Agile squads working in two-week sprints and reports directly to the Chief Technology Officer, giving the hire significant architectural influence and visible impact. A major theme of the position is exploring and embedding artificial intelligence capabilities — from chatbots to developer-assist tooling — across the business.

Responsibilities - Design and build scalable, high-throughput backend services applying SOLID principles and modern engineering best practice. - Architect components across a Microsoft technology stack with services hosted on a leading public cloud platform. - Collaborate closely with product, design, and other engineering squads inside an Agile delivery model running two-week sprints. - Act as a champion of code quality, delivery discipline, and on-schedule release execution. - Identify and prototype artificial intelligence use cases, including chatbots and tooling that assist developers. - Mentor peers and partner with senior leadership on technical direction.

Requirements - Substantial professional experience as a software engineer working on production systems. - Strong C# backend skills on the .NET stack, with bonus exposure to Python. - Practical knowledge of a major public cloud platform (AWS-class services) and building distributed, scalable systems. - Solid grasp of computer science fundamentals, including object-oriented design, data structures, and design patterns. - Demonstrated — or a clear active interest in — applied artificial intelligence and modern AI developer tooling. - Strong analytical, problem-solving, planning, and stakeholder-communication skills.

Benefits and work setup - Base salary up to roughly £120,000, with a bonus around 20%. - Pension with a 5% employer contribution. - 25 days of holiday, rising to 27 after two years and 30 thereafter. - Life assurance covering four times base salary and an employee assistance programme. - Hybrid arrangement based in London, with two days a week in modern offices and two days remote (Thursdays and Fridays). - Structured training, supported learning, and clear career-development pathways.