Senior .NET Developer

Role Overview

• Lead the migration of the Volunteer Impact backend from VB.NET/.NET Framework to C#/.NET 10, defining the migration approach and executing it incrementally against a live production system
• Modernize a custom security framework (70+ custom attributes) into something that works on the new stack, with zero authorization bypasses
• Strengthen the existing CI/CD pipeline and, with our quality engineering function, wire in the gates that catch functional and performance regressions before they reach production
• Ship migrated areas to production independently and incrementally while the legacy application keeps running
• Become the second engineer who can independently cut, validate, and deploy a production release
• Identify, evaluate, and replace legacy dependencies that don’t have a path forward to modern .NET, without introducing functional or performance regressions
• Make the technical sequencing calls: which areas migrate first, which dependencies get replaced when, and where automated conversion is viable vs. manual rewrite
• Lay the foundation for the team to grow by modernizing the stack to one that any C# developer can contribute to

Requirements

• 8+ years of professional C#/.NET experience, with real depth in the framework, not just the latest version
• You’ve personally led or been the technical anchor on a .NET Framework-to-.NET Core (or later) migration of a large, production monolith serving paying customers
• You’ve migrated a production system incrementally with minimal downtime and can articulate the approach you’d take here
• Deep NHibernate experience is strongly preferred. We’re keeping NHibernate to reduce migration risk, so the value is understanding a mature data access layer, preserving existing behaviour, and knowing where modernization helps without unnecessary churn.
• You’ve replaced legacy dependencies in production: DI containers, bundling frameworks, service hosting, and unsupported third-party libraries. You know how to swap critical components while the plane is flying.
• Hands-on experience with legacy .NET ecosystem components: ASP.NET MVC-to-Core routing, custom security frameworks, and the kinds of dependencies that don’t have a clean upgrade path
• Familiarity with migrating SSRS reports to a modern reporting platform is a benefit. We have a significant reporting footprint, so preserving report behaviour during that move would be valuable.
• You’ve improved CI/CD pipelines for .NET applications and know how to work with a quality function to build gates that catch functional and performance regressions early
• You’re comfortable in a small core team with shared DevOps and DBA support available, and a dedicated quality engineering partner who owns the regression gate across our platforms. You can make sound technical decisions, debug hands-on, and know when to pull the right support in.
• VB.NET familiarity is a bonus, not a requirement. The job is the conversion, not maintaining VB.NET.

Tech Stack

• ASP.NET
• .NET

Benefits

• Medical, dental & vision insurance (after 90 days)
• 401(k) (after 90 days)
• Unlimited vacation + 9 paid holidays
• Paid parental leave
• Competitive comp package