Senior .NET Developer with Azure - banking industry (f/m/x)

Technologies we use

Expected

• C#
• TypeScript
• AzureDevOps
• .NET
• CI/CD
• Microsoft Azure
• Power BI
• React.js
• Terraform
• Module Federation
• Azure SQL DBs
• Microsoft SQL Server
• Databricks

Optional

• Observability
• Automated Testing

About the project

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 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

Our requirements

• 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
• 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
• Practical knowledge of building and securing REST APIs with validation and authentication
• Experience with automated testing frameworks like xUnit and Jest / Vitest
• Familiarity with observability tools such as Application Insights and structured logging
• Good Git practices and code review discipline
• Advanced level of English

Optional

• Knowledge of observability practices
• Experience with automated testing

What we offer

• Great Place to Work since 2015 - it’s thanks to feedback from our workers that we get this special title and constantly implement new ideas
• Employment stability - revenue of PLN 2.1BN, no debts, since 2006 on the market
• We share the profit with Workers - over PLN 76M has already been allocated for this aim since 2022
• Attractive benefits package - private healthcare, benefits cafeteria platform, car discounts and more
• Comfortable workplace – class A offices or remote work
• Dozens of fascinating projects for prestigious brands from all over the world – you can change them thanks to Job Changer application
• PLN 1 000 000 per year for your ideas - with this amount, we support the passions and voluntary actions of our workers
• Investment in your growth – meetups, webinars, training platform and technology blog – you choose
• Fantastic atmosphere created by all Sii Power People

Recruitment stages

• Send your CV
• Talk to us about your expectations
• Learn more about our projects and choose the best
• Start your adventure with Sii!

Sii Sp. z o.o.

Sii is the leading technology consulting, digital transformation, engineering, and business services vendor in Poland. We already employ more than 7 300 professionals and implement projects in a variety of industries for clients from many countries around the world. The Great Place to Work title, won 10 times in a row, proves that at Sii, we create a friendly work environment.

Sii ensures that all employment-related decisions are made solely on the basis of qualifications and competencies. We are committed to equal treatment of all individuals, regardless of any protected characteristics, and promoting a diverse and inclusive work environment.

This is how we work