Czym będziesz się zajmować? Design and implement backend services and APIs in .NET (6/8) with clean architecture.Build and maintain React + TypeScript frontends and incremental migrations from legacy UI.Read, refactor and extract business logic from legacy .NET and T‑SQL (stored procedures).Write and maintain automated tests: unit, integration, contract and e2e.Create and maintain CI/CD pipelines (Azure DevOps / GitHub Actions) and IaC artifacts.Instrument services for observability (metrics, logs, distributed traces) and alerting.Troubleshoot production incidents, deliver fixes and support deployments.Participate in architecture and domain modelling activities (DDD patterns, bounded contexts).Collaborate in Agile ceremonies, estimate work and define acceptance criteria.

Kogo poszukujemy? 5+ years commercial experience with C# and .NET (Framework + .NET Core / .NET 6+).Strong experience with EF Core and MSSQL (query tuning, transactions, indexing).Production experience with React and TypeScript.Practical experience building and securing REST APIs (validation, versioning, auth).Familiarity with Azure services (App Service, Functions, Azure SQL, Storage, Service Bus).CI/CD and automated testing experience (xUnit, Jest, Playwright/Cypress).Observability knowledge (Application Insights / OpenTelemetry, structured logging).Ability to read and reason about legacy codebases (ASP.NET MVC, Razor, WPF, WinForms).Good Git practices and code review discipline.English for technical communication (B2+).