Avanti Recruitment is partnering with a Sheffield-based software development company with over 20 years of expertise building operational systems for secure and specialist environments. Their technology is used in critical, real-world settings with long-term client relationships built on tailored solutions. You''ll join their development team to lead the modernisation of their core booking and ticketing system, migrating from .NET Framework and legacy VB.NET to modern .NET Core. This system is central to their business operations, making this a high-impact role from day one. Technical Development: Migrate core systems from .NET Framework/VB.NET to .NET Core Develop bespoke software solutions using .NET and C# Build APIs and integrate with existing operational systems Client Interaction: Work directly with clients to gather and clarify requirements Collaborate throughout the full software lifecycle from proposals to deployment Write documentation and coordinate release management Essential Skills Strong .NET and C# experience SQL Server proficiency API development experience UK Driving License and vehicle access Eligible for UK Government SC Clearance Desirable Skills Angular or Node.js exposure Azure cloud experience VB.NET knowledge (helpful for migration work) Working Arrangements First 6 months: 4 days/week in Sheffield office Ongoing: 2 days/week in office Benefits Salary: 35,000 - 48,000 based on experience Performance bonus: Bi-annual (last year averaged 3-4k ..... full job details .....