Senior FullStack .NET Developer

Avanti is working with an established software business that is investing heavily in the modernisation of one of it's core platforms and is looking for a Senior Fullstack .NET Developer with strong experience in React.

This is a hands-on engineering role where you'll help evolve an established business-critical application into a more modern, scalable architecture.

The focus will be on improving the underlying platform, building modern services and APIs, increasing automated test coverage and gradually moving functionality towards a modern web-based frontend.

You'll remain very hands-on with C#/.NET development while also contributing to software design, architecture and technical decisions across the wider engineering team.

The business places a strong emphasis on the engineering quality, automated testing and test-first development, so strong TDD experience is essential.

What you'll be doing

Building and maintaining applications and services using C# and modern .NET

Designing and developing REST APIs

Developing frontend functionality using React

Helping modernise an established application architecture

Improving automated test coverage and overall code quality

Working in a test-first development environment

Contributing to software design and architecture decisions

Improving platform maintainability, scalability and long-term technical direction

Supporting existing systems while helping build their future replacement

Technology Environment:

C# / .NET 8

REST APIs

React

SQL Server

Automated testing

TDD

CI/CD

Cloud technologies

There is also some exposure to established desktop WinForms technologies within the existing platform, although previous experience in this area is not essential.

Essential Skills:

Strong C#/.NET

React

TDD

REST APIs

CI/CD knowledge

Experience contributing to architecture / design and technical decisions

Ability to work independently and take ownership of technical problems

Experience with cloud platforms, legacy application modernisation or AI-assisted development would be usefu...