Senior .NET Engineer

Description

Summary: Seeking a Senior .NET Engineer to decompose a legacy desktop application into modern backend services using ASP.NET Core, focusing on design, implementation, and collaboration. Highlights: 1. Contribute to the decomposition of a legacy desktop application 2. Design and implement backend components aligned with target architecture 3. Collaborate with team members to define scalable data access approaches We are looking for a **Senior .NET Engineer** to 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 **We offer** * International projects with top brands * Work with global teams of highly skilled, diverse peers * Healthcare benefits * Employee financial programs * Paid time off and sick leave * Upskilling, reskilling and certification courses * Unlimited access to the LinkedIn Learning library and 22,000\+ courses * Global career opportunities * Volunteer and community involvement opportunities * EPAM Employee Groups * Award\-winning culture recognized by Glassdoor, Newsweek and LinkedIn