Lead Software Engineer

The Difference Engine; Greater London; On-site; Full time

Job summary

A leading recruitment agency is seeking a Lead or Senior Software Engineer for a growing fintech company in London. This role involves designing and delivering features using C# and the .NET framework, while collaborating with stakeholders and mentoring junior engineers. The ideal candidate has at least 8 years of experience and a strong command of cloud technologies such as AWS. If you're looking for a greenfield project with a motivated team, this opportunity is for you.

Qualifications

• Minimum 8 years of professional software engineering experience.
• Extensive experience with C# and .NET framework.
• Strong SQL skills for database design and optimization.
• Proven track record as a senior frontend engineer.
• Comfortable working in cloud environments like AWS.

Responsibilities

• Design and deliver production features in a cloud environment.
• Mentor junior engineers and produce high-quality code.
• Collaborate with stakeholders, including Product.

Skills

C#

.NET framework

Cloud environments

SQL

API integration

Design patterns

Job description

New Year, new challenge? If you're a Lead or Senior software engineer with a track record of using C#, and the .NET framework we'd love to talk to you.

We've been retained by our London client to help them find a senior leader for their engineering team as they look to re-engineer a highly successful platform relied on by some of the biggest names in asset management and banking. Core to the solution is their selection of C# / .NET framework to build the next generation of their software.

This is a rare opportunity to join a greenfield project as the company look to design their run away success application from the ground up. New stack (C#, .NET) and new architecture - this represents a great chance to put your design and programming skills to work right at the start.

Our client is a successful Fintech, underwritten by P.E. investment, growing 30% YoY, which has a very strong balance sheet and highly focused and motivated leadership team.

We're looking forward to speaking to senior and lead C#, .NET engineers with the following profile:-

• A minimum 8 years of professional software engineering experience, with extensive experience working with C# and the .NET framework.
• Comfortable working in cloud environments, our client has selected AWS, but experience with other cloud techs - Azure, GCP also of interest
• Proven track record as a hands-on senior frontend engineer - you design and deliver production features while supporting team development
• Strong software engineering fundamentals: Object-oriented programming, design patterns, SOLID principles, automated testing, CI/CD
• API integration: Experience consuming REST APIs, handling asynchronous data, error handling, and loading states
• Modern database knowledge: Strong SQL skills, database design, and optimisation

You'll be happy producing high quality code and collaborating closely with key stakeholders, including Product. As a senior C# developer you'll also be comfortable guiding and mentoring more junior engineers. This is a role that comes with a high degree of autonomy and there is an expectation that you will be passionate about your craft and build that culture around you.

If this sounds like the move you're looking for in 2026, please get in touch us and we'd be happy to share further details with you.

TheDifferenceEngine is a recruitment agency, retained by our client to help them find the best in the market. Promising candidates can be assured of a typical 24 hour response from initial contact.