Senior .NET Developer
About The Position
Our flagship product, Volunteer Impact, is a mature, revenue-generating platform built on VB.NET and .NET Framework. It works. It serves thousands of organizations. And it needs to move to .NET 10 and C# so we can hire, ship, and build on a modern stack. You’ve done this before. You’ve been the technical anchor on a .NET Framework-to-modern-.NET migration of a real production monolith where downtime had to be tightly managed. You know how to migrate incrementally without breaking a live system, and your opinions come from experience, not theory. You’ve lived in NHibernate, swapped out legacy DI containers and dead dependencies, and dealt with custom security frameworks that predate ASP.NET Core’s policy model. You’re still hands-on. You write code daily, configure your own CI pipelines, and can replace a legacy dependency, validate the regression risk, and ship the change to production. You want a role where you own the company’s most important technical initiative, not one where you draw architecture diagrams and hand them off. You do serious work with a small core team, supported by fractional DevOps and release expertise when it matters, and a dedicated quality engineering function that owns the regression gate protecting this migration. You own the technical path, make sound trade-offs, and work directly with those partners to move the platform forward. You’re here to build the engineering foundation, not inherit one.
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
- 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.
Nice To Haves
- 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.
- VB.NET familiarity is a bonus, not a requirement. The job is the conversion, not maintaining VB.NET.
Responsibilities
- 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
Benefits
- Medical, dental & vision insurance (after 90 days)
- 401(k) (after 90 days)
- Unlimited vacation + 9 paid holidays
- Paid parental leave
- Competitive comp package
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What This Job Offers
Job Type
Full-time
Career Level
Senior
Education Level
No Education Listed
