Senior .NET Developer with Azure

We are looking for a versatile Senior .NET Developer to join the modernization program, migrating a portfolio of legacy applications to a cloud-native Azure architecture. In this role, you will work on a variety of tasks across backend, frontend, database, and cloud/DevOps, contributing to the development of .NET APIs, React microfrontends, and Azure services. This position is based in Cracow and offers a hybrid work model. If you are passionate about modernizing applications and enjoy working in a collaborative environment, this opportunity may be the right fit for you. Your tasks Designing and implementing backend services and REST APIs in .NET 9 using Clean ArchitectureBuilding and maintaining React + TypeScript microfrontendsEvolving MSSQL / Azure SQL schemasAuthoring and maintaining Infrastructure as Code in Terraform for Azure resource managementBuilding, optimizing, and supporting CI/CD pipelines in Azure DevOpsIntegrating Azure AD authentication and applying security best practicesInstrumenting services for observability and health checksReading, refactoring, and extracting business logic from legacy .NET and T-SQL during migrationWriting and maintaining automated tests including unit, integration, and E2E testsTroubleshooting production incidents and supporting deployments Requirements Minimum 5 years of commercial full-stack experience with C# /.NET (including .NET 6+/9) and ASP.NET CoreStrong skills in EF Core and MSSQL / Azure SQL, including query tuning and stored proceduresHands-on experience with Azure services such as App Service, Azure SQL, and FunctionsProficiency in Infrastructure as Code using Terraform for multi-environment provisioningExperience with CI/CD processes in Azure DevOps, including YAML pipelines-as-codePractical knowledge of building and securing REST APIs with validation and authenticationExperience with automated testing frameworks like xUnit and Jest / VitestFamiliarity with observability tools such as Application Insights and structured loggingGood Git practices and code review disciplineAdvanced level of English Nice to have Knowledge of observability practicesExperience with automated testing Job no. JOB-7CTY4 Sii ensures that all hiring decisions are made solely on the basis of qualifications and competence. We are committed to equal and fair treatment of all, regardless of legally protected characteristics. At Sii, we promote a diverse and inclusive work environment, in full compliance with applicable anti-discrimination laws. Benefits For You Great Place to WorkSolid financial situationContracts with the biggest brandsCentre of internal trainingsMany experts you can learn fromOpen and accessible management teamProfit sharingPassion Sponsorship programRegular integration events and tripsComfortable and well-equipped officesMySii appMedical care