Senior .NET Developer — Cloud-Native Azure & Microfrontends

Sii Poland

Kraków

Hybrid

PLN 180,000 - 300,000

Full time

3 days ago

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Benefits offered by this job

Great Place to Work

Profit sharing

Medical care

Centre of internal trainings

MySii app

Regular integration events and trips

Comfortable offices

Job summary

Sii Poland in Kraków is seeking a versatile Senior .NET Developer to join a modernization program migrating legacy applications to a cloud-native Azure architecture. You will work across backend, frontend, database, and DevOps, contributing to .NET APIs, React microfrontends, and Azure services in a hybrid setup.

The role involves Terraform IaC, Azure DevOps pipelines, security best practices, and observability efforts.

Qualifications

Minimum 5 years of commercial full-stack experience with C#/ .NET including .NET 6+/9 and ASP.NET Core.
Strong skills in EF Core and MSSQL / Azure SQL, including query tuning and stored procedures.
Practical knowledge of building and securing REST APIs with validation and authentication.
Experience with automated testing frameworks like xUnit and Jest / Vitest.
Hands-on experience with Azure services such as App Service, Azure SQL, and Functions.
Proficiency in Infrastructure as Code using Terraform for multi-environment provisioning.
Experience with CI/CD processes in Azure DevOps, including YAML pipelines-as-code.
Familiarity with observability tools like Application Insights and structured logging.
Good Git practices and code review discipline. Advanced level of English.

Responsibilities

Designing and implementing backend services and REST APIs in .NET 9 using Clean Architecture.
Building and maintaining React + TypeScript microfrontends.
Evolving MSSQL / Azure SQL schemas.
Authoring and maintaining Infrastructure as Code in Terraform for Azure resource management.
Building, optimizing, and supporting CI/CD pipelines in Azure DevOps.
Integrating Azure AD authentication and applying security best practices.
Instrumenting services for observability and health checks.
Reading, refactoring, and extracting business logic from legacy .NET and T-SQL during migration.
Writing and maintaining automated tests including unit, integration, and E2E tests.
Troubleshooting production incidents and supporting deployments.