Senior C# Developer (Desktop - Web migration)

Chalvey, Slough💼 Full-time💰 $65,000–$65,000🗓 2026-05-12 → 2026-08-07

Core

Senior developer leading the migration of a large-scale legacy on-premise desktop platform to a modern .NET Core cloud-based architecture.

Role type

Senior IC .NET/C# developer (legacy modernization)

Builds

Cloud-based web applications replacing on-premise desktop systems

Domain

Enterprise software, legacy modernization, cloud migration

Deliverable

production ML models | product features | infrastructure

Required skills

C#, .NET Framework, .NET Core, WinForms, MS SQL Server, refactoring, CI/CD, TDD, cloud experience

Preferred skills

legacy system migration, React, JavaScript

Technologies

C#, .NET Framework, .NET Core, WinForms, MS SQL Server, React, JavaScript, CI/CD tools

Responsibilities

Assess and improve established C# codebase built on older Microsoft technologies, migrate legacy desktop applications to web/cloud, influence technical direction for 40+ projects, collaborate with CTO and engineering team

Seniority

Senior, hands-on IC

Sourced via adzuna · Listed on CareerPlan, which tracks 70,000+ jobs from 20+ sources.

About Avanti Recruitment

Avanti Recruitment is working with a growing, technology-led business based in Slough, that is undergoing a major systems transformation following a recent acquisition. As part of this programme, they are looking to hire a Senior .NET / C# Developer to play a key role in evolving a large-scale legacy platform and supporting its transition from an on-premise desktop environment to a modern, .NET Core, cloud-based architecture. This is a great opportunity for someone who enjoys solving complex engineering challenges and has experience moving legacy or desktop-based applications towards modern we