Senior .NET Developer

Avanti Recruitment; Langley; On-site; GBP 65,000 - 80,000; Full time

Benefits offered by this job

Hybrid working

Onsite collaboration

Leadership exposure

Long-term progression

Job summary

Avanti Recruitment in the United Kingdom is seeking a strong C# developer to join a technology-led business undergoing a major systems transformation. You will help evolve a large-scale legacy platform from on-premise desktop to a modern .NET Core, cloud-based architecture, working closely with the CTO and engineering team.

Hybrid working is offered with onsite collaboration early on; the role offers significant technical ownership, leadership exposure, and long-term progression across ~40

Qualifications

• Strong experience with C# development.
• Experience with .NET Framework and .NET Core.
• Hands-on experience with WinForms or other desktop application development.
• Experience with MS SQL Server.
• Experience with refactoring and modernisation projects.
• Experience working in agile environments.
• Familiarity with CI/CD practices.
• Experience with testing methodologies such as TDD.
• Cloud experience.
• Experience migrating legacy systems.
• Exposure to React or JavaScript.
• Comfortable working onsite regularly during the early stages of a project in a hybrid setup.

Responsibilities

• Assess, improve, and progressively enhance an established C# codebase built on older Microsoft technologies.
• Help evolve a large-scale legacy platform from an on-premise desktop environment to a modern .NET Core, cloud-based architecture.
• Work closely with the CTO and wider engineering team on technical direction.
• Contribute to planning, collaboration, and technical workshops.
• Support the transition from legacy desktop applications toward modern web and cloud platforms.
• Help manage and influence a major systems transformation programme.
• Work across multiple projects in the transformation pipeline.
• Bring ‘greenfield’ thinking within an established business.
• Participate in leadership and architecture decisions.
• Contribute as part of a small, collaborative engineering team.

Skills

C#

.NET Framework

.NET Core

WinForms

JavaScript

React

Agile

TDD

CI/CD

Cloud

SQL

Tools

MS SQL Server

Job description

Salary: £65,000 - 80,000 per year

Requirements

• We are looking for strong experience with C# development.
• We require experience with .NET Framework and .NET Core.
• We need hands‑on experience with WinForms or other desktop application development.
• We require experience working with MS SQL Server.
• We are looking for experience with refactoring and modernisation projects.
• We require experience working in agile environments.
• We need familiarity with CI/CD practices.
• We require experience with testing methodologies such as TDD.
• We are looking for cloud experience.
• We would value experience migrating legacy systems.
• We would value exposure to React or JavaScript.
• We are looking for someone comfortable working onsite regularly during the early stages of a project in a hybrid setup.

Responsibilities

• We will have you assess, improve, and progressively enhance an established C# codebase built on older Microsoft technologies.
• We will have you help evolve a large-scale legacy platform from an on‑premise desktop environment to a modern .NET Core, cloud‑based architecture.
• We will have you work closely with our CTO and wider engineering team on technical direction.
• We will have you contribute to planning, collaboration, and technical workshops.
• We will have you support the transition from legacy desktop applications toward modern web and cloud platforms.
• We will have you help manage and influence a major systems transformation programme.
• We will have you work across multiple projects in the transformation pipeline.
• We will have you bring greenfield thinking within an established business.
• We will have you participate in leadership and architecture decisions.
• We will have you contribute as part of a small, collaborative engineering team.

Technologies

• .NET Framework
• C#
• CI/CD
• Cloud
• CTO
• Support
• JavaScript
• React
• SQL
• TDD
• Web
• ASP.NET
• Frontend

More

We are a growing, technology‑led business based in Slough, undergoing a major systems transformation following a recent acquisition. This is a high‑impact opportunity to join at a pivotal stage of our journey, with around 40 projects in the pipeline and the chance to shape the future of our platform. We offer hybrid working, although we would ideally like someone who can attend onsite regularly during the early stages for collaboration and technical workshops. This role offers significant technical ownership, direct access to leadership, and long‑term progression as our technology function continues to grow. The salary for this position is £65,000 to £80,000 plus benefits.

last updated 33 week of 2026