Senior .NET Developer – Energy B2B Platform

About the role

Join a leading energy‑focused technology team as a Senior Developer, responsible for a key B2B customer portal and its ecosystem of APIs. You will help modernise the business with AI‑enabled tools while delivering stable, secure, and high‑performing services.

Key responsibilities

• Own the B2B customer portal and its connected APIs and integrations.
• Design, build and enhance RESTful back‑end services using C# and ASP.NET.
• Maintain and improve the integration layer across core systems, ensuring stability and security.
• Support delivery through an agile SDLC, writing quality tests and collaborating with analysts and data owners.
• Shape the internal development function, driving modernisation and AI tooling adoption.

Required profile

• Proven senior‑level experience delivering production‑grade .NET applications.
• Strong understanding of API and service‑oriented architecture.
• Solid experience with Microsoft SQL Server, including optimisation and stored procedures.
• Hands‑on experience deploying to Microsoft Azure, including Linux‑hosted environments.
• Familiarity with engineering best practices such as Git/GitHub workflows and agile tools (Jira, Confluence).

Required skills

• C#
• .NET Framework
• ASP.NET
• REST APIs
• Razor Pages / MVC
• Microsoft SQL Server
• Azure
• Linux hosting
• Git / GitHub
• Jira
• Confluence

What we offer

• Competitive salary (£75,000) and strong benefits package (enhanced pension, private medical, life insurance, income protection).
• Day off on your birthday, free parking, fresh fruit/snacks/breakfast.
• Career progression as the internal development function expands, with visibility in technical decision‑making.
• Profit share, company parties and a community‑focused office environment.