Senior Back-end Developer (.NET)

Experience and Skills

• 5+ years of professional experience in backend development with .NET / C#
• C1 English level or higher
• Proven production experience with Clean Architecture and CQRS patterns (MediatR or similar)
• Strong MySQL expertise with Dapper for high-performance queries and EF Core for domain management
• Hands-on AWS experience: Fargate, RDS
• Demonstrated focus on unit and integration testing

Skills

• .NET 8+
• C#
• Clean Architecture
• CQRS
• MediatR
• MySQL
• Dapper
• EF Core
• AWS Fargate
• AWS RDS
• Unit Testing
• Integration Testing

Projects

You will lead the migration of a legacy system to a modern .NET 8+ backend under Clean Architecture. Working in a high-availability environment with complex business rules and strict security regulations, you will translate legacy logic into robust Web APIs, optimize MySQL data access, and implement secure authentication flows. Your work directly enables reliable integration with payment providers and frontend systems in a regulated domain where technical precision is critical.

Key Responsibilities

• Migrate complex legacy business logic to modern .NET 8+ Web APIs following Clean Architecture principles (Domain, Application, Infrastructure)
• Design and implement secure, robust APIs with strict authentication flows and compliance-mandated session timeouts
• Optimize MySQL data access: Dapper for performance-critical paths, EF Core for standard domain operations
• Define clear API contracts for frontend integration and payment provider connectivity (Braintree/Paymentech)