Senior Backend Engineer (C# / .NET)

We are **tech transformation** specialists, uniting human expertise with AI to create scalable tech solutions. With over 8,000 CI\&Ters around the world, we’ve built partnerships with more than 1,000 clients during our 30 years of history. Artificial Intelligence is our reality. Your primary mission will be to drive the delivery of scalable system enhancements that expand business capabilities and support seamless multi\-brand operations.  You will be responsible for designing and evolving a modular application architecture capable of handling flexible data models and growing operational demands. By improving the reliability, performance, and maintainability of our current solutions, you will ensure a sustainable platform evolution that accommodates future integrations and parallel initiatives. Additionally, you will play a key role in promoting structured knowledge transfer to strengthen internal ownership and foster long\-term development autonomy  **Key Responsibilities:** * Design, build, and maintain backend microservices and integrations using .NET 8/9 and ASP.NET Core within a CQRS \+ Clean Architecture ecosystem. * Contribute to solution design, making informed trade\-offs around performance, scalability, and maintainability. * Develop RESTful APIs (command/query separation) and integrate systems using event\-driven patterns (Azure Service Bus). * Implement and maintain background processing using Azure Functions and message\-driven workflows. * Work with Azure SQL and Entity Framework Core, including data modelling and query optimisation. * Apply structured patterns to ensure code quality, maintainability, and consistency. * Follow and contribute to security best practices using Azure Entra ID (OAuth2/OIDC, JWT). * Contribute to CI/CD pipelines (Azure DevOps) and support containerised deployments (Azure Container Apps). * Troubleshoot production issues using Application Insights, logs, and distributed tracing. * Collaborate with cross\-functional teams and participate in technical discussions and design reviews. * Support knowledge sharing and help mentor less experienced engineers. **Required Skills and Qualifications:** * Strong experience with C\# and .NET (ASP.NET Core, .NET 6\+) in production environments * Experience building microservices and RESTful APIs * Familiarity with event\-driven systems (Azure Service Bus or similar) * Good knowledge of Azure SQL and Entity Framework Core * Experience with Clean Architecture, CQRS, or similar patterns * Hands\-on experience with background processing (Azure Functions or worker services) * Familiarity with Docker and cloud\-native environments * Experience with CI/CD pipelines (Azure DevOps or similar) * Ability to troubleshoot issues using logs and monitoring tools * Strong communication skills and ability to work in team environments * Advanced English * Ownership of tasks and commitment to delivering quality outcomes. * Strong communication with technical and non\-technical stakeholders. * Ability to manage priorities in a dynamic environment. * Collaborative mindset and willingness to support team growth. **Nice\-to\-have Skills:** * Experience with event\-driven architectures and asynchronous processing. * Exposure to modernisation or migration initiatives. * Familiarity with Azure Entra ID and secure authentication flows. * Basic knowledge of observability tools (Application Insights, OpenTelemetry). **Our benefits:** \-Health and dental insurance \-Meal and food allowance \-Childcare assistance \-Extended paternity leave \-Partnership with gyms and health and wellness professionals via Wellhub (Gympass) TotalPass; \- Profit Sharing and Results Participation (PLR); \-Life insurance \- Continuous learning platform (CI\&T University); \-Discount club \-Free online platform dedicated to physical, mental, and overall well\-being \-Pregnancy and responsible parenting course \-Partnerships with online learning platforms \-Language learning platform And many more! More details about our benefits here: https://ciandt.com/br/pt\-br/carreiras At CI\&T, inclusion starts at the first contact. If you are a person with a disability, it is important **to present your assessment during the selection process. *See which data needs to be included in the report by clicking here* . This way, we can ensure the support and accommodations that you deserve. **If you do not yet have the assessment, don't worry: we can support you in obtaining it. We have a dedicated Health and Well\-being team, inclusion specialists, and affinity groups who will be with you at every stage. Count on us to make this journey side by side.****