Senior .NET Developer (AI-Enabled) Company Our client is on a mission to help small businesses turn their bold ambitions into reality. Their lending products make access to capital faster, fairer, and more flexible, enabling SMEs to grow with confidence. They have provided millions in funding to hundreds of UK businesses, with their loan book growing 4x in 2025 — and they are just getting started. They are a friendly and collaborative team with a fast-paced, high-performing culture. Headquartered in London, with team members across Nigeria, South Africa, and the UK, the business is backed by top-tier investors and has recently closed a £49M equity and debt Series A investment round to significantly scale operations across the UK in 2026.

Position Overview

Our client is seeking a highly experienced Senior .NET Developer with deep technical expertise across the Microsoft technology stack. This is a critical hire for someone who understands systems end-to-end — from database architecture and optimisation through to API design and scalable backend services.

This role requires a very senior engineer who combines strong corporate experience with hands-on technical depth, and who actively leverages AI tools to enhance productivity, code quality, testing, and solution design.

Key Responsibilities

Architecture & Development

• Design, develop, and maintain enterprise-grade applications using .NET and C#.

• Build and optimise RESTful APIs and backend services.

• Architect and maintain robust database structures (SQL Server or similar), ensuring performance and scalability.

• Drive system performance tuning, security, and reliability best practices.

• Contribute to high-level architectural decisions and technical strategy.

AI-Enabled Engineering

• Use AI development tools to supercharge coding efficiency, debugging, refactoring, and documentation.

• Apply AI-assisted approaches to testing, code review, and architectural planning.

• Contribute to integrating AI-driven capabilities into products where appropriate.

• Stay current with emerging AI tooling and modern engineering practices.

Corporate & Enterprise Delivery

• Operate effectively within structured corporate governance and compliance environments.

• Collaborate closely with cross-functional teams including Product, Risk, Operations, and Leadership.

• Ensure solutions meet enterprise standards for scalability, maintainability, and security.

Technical Leadership

• Provide mentorship and guidance to mid-level and junior developers.

• Promote engineering excellence, clean code principles, and best practices.

• Support continuous improvement of development frameworks, standards, and tooling.

Qualifications / Required Skills

• 8+ years of experience in .NET and C# development.

• Strong expertise across the Microsoft stack (.NET Core, ASP.NET, SQL Server; Azure is advantageous).

• Deep understanding of:

  • Database design and optimisation

  • API architecture and integration

  • System scalability and performance engineering

• Proven experience within corporate or enterprise environments.

• Demonstrated ability to effectively use AI tools to enhance development workflows.

• Strong understanding of software architecture principles and clean coding standards.

• Excellent analytical, problem-solving, and communication skills.

Nice to Have

• Experience with Azure cloud architecture and DevOps practices (CI/CD, containerisation).

• Exposure to AI/ML concepts or experience integrating AI services into applications.

• Experience in fintech, financial services, or regulated environments.

• Experience working in distributed or international teams.

What You’ll Get

• The opportunity to work in a fast-scaling, high-growth fintech environment.

• Exposure to complex, enterprise-grade systems and architectural decision-making.

• A collaborative, high-performing engineering culture.

• Competitive salary and benefits.

• The opportunity to leverage AI-first development practices in a modern technology environment.