Sr C# Developer (Migration)

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. 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 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.

• 8+ years building production Java microservices (Spring Boot or similar)
• Can read unfamiliar Java code and explain what it does and why
• 5+ years hands-on C# and .NET Core / .NET 6+, ASP.NET Core Web APIs, dependency injection, async patterns
• Has personally converted or re-platformed code between languages or frameworks
• Microservices and REST: API design, service-to-service communication, containerization (Docker), CI/CD
• Comfortable proving parity with automated tests, not visual inspection
• Works independently, translates technical detail for business stakeholders, gives direct feedback
• Experience using AI coding tools (GitHub Copilot, Claude, ChatGPT, or similar) for code conversion or large refactors
• Familiarity with LLM-assisted development workflows: prompt design, output validation, agentic coding tools
• Kubernetes, AWS or Azure, API gateways (Kong)
• Exposure to MySQL and SQL Server
• Exposure to Python (for tooling around the conversion pipeline)