Senior .NET Engineer

We are looking for aSenior .NET Engineerto join the migration team, working on the decomposition of a .NET Framework 4.8 / VB.NET desktop application into ASP.NET Core (Current) backend services on Kubernetes. The engagement starts with the highest-risk item in the project — characterising and replacing a 14,518-line VB.NET data layer with EF Core repositories against a multi-tenant PostgreSQL schema with Row-Level Security — then continues across backend services depending on team allocation.

All services follow the same patterns throughout: ASP.NET Core, EF Core, PostgreSQL, JWT tenant middleware, Docker, Kubernetes manifests.

Responsibilities

• Contribute to the decomposition of a legacy desktop application into modern backend services
• Design and implement backend components aligned with the target architecture and established patterns
• Collaborate with team members to define scalable data access approaches for multi-tenant scenarios
• Participate in code reviews and share technical insights to raise overall code quality
• Analyze legacy business logic to ensure functional parity across newly built services
• Take part in architectural discussions and help refine technical direction across workstreams
• Investigate and resolve issues encountered throughout the migration lifecycle
• Support deployment activities and help ensure services run reliably in containerised environments

Requirements

• At least 3 years of professional relevant experience in backend .NET engineering on production systems
• Hands-on delivery of REST APIs consumed by a real frontend within a team environment
• Familiarity with containerised deployments, including shipping services running in Docker
• Confident, production-level command of C# and ASP.NET Core (Current)
• Practical experience with Entity Framework Core, including migrations, global query filters, and optimistic concurrency
• Applied knowledge of OAuth 2.0 and OIDC server-side flows using Microsoft.Identity.Web, along with JWT validation and tenant middleware
• Experience with Docker covering multi-stage builds, secrets handling, and CI image gates
• Hands-on background with xUnit and Testcontainers, with the ability to write meaningful integration tests against a real database
• Strong VB.NET reading comprehension, with the ability to follow and reason about legacy VB.NET code without needing to write it
• Confident English communication at B2 level or higher, in both written and spoken forms

Nice to Have

• Experience with PostgreSQL covering schema design, indexing, and multi-tenant data patterns
• Familiarity with Helm for managing Kubernetes application deployments
• Working knowledge of Kubernetes for container orchestration and service operations
• Applied understanding of OAuth2 for securing modern web applications and APIs
• Exposure to Visual Basic .NET for interpreting or maintaining legacy components
• Awareness of XBRL for structured business reporting scenarios