Sr C# Developer (Migration)
Summary
Remote senior developer converting a client's Java microservices to C#/.NET: taking AI-generated first drafts, hand-finishing them to the client's C# patterns, mapping Java idioms (Spring, JPA, Maven) to .NET equivalents, and proving functional parity with automated tests. Needs 8+ years Java and 5+ years C#/.NET.
This is a remote position.
About the role
IL6 is C#-heavy. This is a C#-first role: the must-have is strong C# / .NET, and Java is a genuine plus that breaks ties, not a gate. Do not reject strong C# candidates for weak Java on this one. The developer will build and evolve C# services as part of Client's data migration and API work, including the data access layer and API surface pointed at the consolidated MySQL database.
What you will do
• Build and maintain C# / .NET services in the IL6 codebase.
• Contribute to the rebuilt data access layer and the new API design as 30 databases consolidate into one MySQL instance.
• Design and implement REST APIs to stable contracts, including versioning and consumer segmentation (app, integration, reporting).
• Tune data access for performance (EF Core or Dapper, query design, indexing, caching).
• Write automated tests and support CI/CD.
Must have
• Strong C# / .NET: 8+ years, deep with .NET Core / .NET 6+, ASP.NET Core Web APIs, dependency injection, async/await.
• Data access depth: EF Core and/or Dapper, connection management, query performance, SQL (MySQL or SQL Server).
• API design: REST contract design, versioning, pagination, error handling.
• Microservices and CI/CD: service-to-service communication, containerization, pipelines.
• Communication: works independently, gives direct feedback, translates for stakeholders.
Nice to have (tie-breakers)
• Java exposure, enough to read and reason about Java services during the migration. Valued, not required.
• Migration or modernization experience.
• AI coding tool experience; interest in AI-assisted development.
• Kong, Azure or AWS, GraphQL.