Senior .NET Developer

Avanti Recruitment

Glasgow

On-site

GBP 60,000 - 75,000

Full time

6 days ago

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Benefits offered by this job

NEST Pension

Bupa Listening Ear

Westfield Rewards

25 days holiday + Bank Holidays

Job summary

Avanti Recruitment is partnering with a growing tech-led software business near Heathrow Airport to hire a Senior C#/.NET Developer. You will take ownership of a large, business-critical WinForms platform that has migrated to .NET 8, helping evolve it with modern engineering practices, improving maintainability and automated testing.

You will stay hands-on with C#/.NET while shaping architecture and software design, collaborating with the CTO, Head of Engineering and the original author to guide

Qualifications

Excellent hands on development with modern .NET / C#
Previous meaningful experience with WinForms
Commercial TDD – Test first (Red / Green / Refactor)
Strong automated testing
Experience contributing to technical decisions and software design
Ownership / modernisation of existing applications

Responsibilities

Modernise the WinForms desktop platform to .NET 8 and Beyond
Contribute to software design and architectural decisions
Drive automated testing and CI/CD improvements
Collaborate with CTO, Head of Engineering and original author to guide the platform's evolution

Skills

C# / .NET

WinForms

TDD / Automated testing

API design

Tools

Visual Studio

Azure

SQL Server

CI/CD

Job description

I'm working with a growing tech-led software business that is heavily investing in its core engineering platform following a recent acquisition. The company is based near Heathrow Airport.

You'll be a Senior C#/.NET Developer taking ownership of a large, business-critical WinForms platform which has recently been migrated from .NET Framework to .NET 8. You'll help evolve the existing application using modern .NET engineering practices, improving its maintainability, automated testing and longer-term technical direction.

The platform currently has limited automated test coverage, so strong practical testing experience is important. The engineering team follows test-first TDD, so you must already have commercial experience working this way.

You’ll remain very hands-on with C#/.NET development while also contributing to software design, architecture and technical decisions. You’ll work closely with the CTO, Head of Engineering and the original software author, gaining a deep understanding of the platform before helping drive the next phase of its evolution.

Working pattern:

During your initial onboarding and knowledge transfer, you will spend 1-2 weeks onsite immersing yourself into the platform/team and the business. Then you will be remote, with the expectation of being in office once every 1-2 months.

What you'll be doing:

The first 12-18 months will focus on modernising an established WinForms desktop platform running on .NET 8, supporting new business functionality, improving maintainability and introducing stronger engineering practices, automated testing and TDD.

You don't need to be using WinForms in your current role, however you need to be comfortable taking ownership of an existing WinForms codebase and evolve it using modern engineering practices. Beyond that, you'll help shape the future architecture as the platform evolves through APIs, cloud services and modern web technologies.

This is a genuine opportunity to influence technical direction within a collaborative engineering team where your ideas will have a real impact.

Current Technology Stack

C#
.NET Framework
Modern .NET (.NET 8)
WinForms
SQL Server
REST APIs
CI/CD
Automated Testing / TDD
Azure (future direction)
React on the frontend

To be considered you must have experience with:

Excellent hands on development with modern .NET / C#
Previous meaningful experience with WinForms
Commercial TDD – Test first (Red / Green / Refactor)
Strong automated testing
Experience contributing to technical decisions and software design
Ownership / modernisation of existing applications

Highly Desirable

Experience migrating WinForms applications to modern .NET.
Clean Architecture.
API design and service-based architecture.
React or JavaScript exposure.
AI-assisted development or Python experience.

The Type of Person Who Will Succeed

You are still very hands on with .NET / C# development, you follow TDD (writing test before code), like improving large existing applications rather than rewriting them from scratch, want to influence architecture, enjoy modernising legacy software and want to take ownership of a platform that is critical to the business.

The key requirement is that you have genuine commercial WinForms experience and are excited by the opportunity to take ownership of a mature Windows desktop platform.

During an interview you will be asked how you would CI/CD a WinForms application and will be asked to run through a coding solution following TDD.

Interview Process

Stage 1: Video interview covering your recent hands-on development experience, engineering approach and technical decision making.

Final Stage: Video interview including a collaborative technical discussion and practical C# coding exercise following TDD, with the engineering leadership team.

Benefits