Master 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. As a key technical leader, you will deliver scalable system enhancements to enable multi\-brand operations and ensure the sustainable evolution of our platform.  You will design flexible application architectures to support modular integrations and meet increasing operational demands while optimizing the performance and reliability of existing solutions. Beyond technical delivery, you will be instrumental in enabling future parallel initiatives and fostering a culture of structured knowledge transfer, ultimately strengthening internal ownership and long\-term development autonomy  **Key Responsibilities:** * Design, build, and evolve highly scalable backend microservices and integrations using .NET 8/9 and ASP.NET Core within a CQRS \+ Clean Architecture ecosystem. * Own end\-to\-end technical solutions, making design decisions and trade\-offs across performance, scalability, resilience, and cost. * Develop and optimise RESTful APIs (command/query separation) and event\-driven systems via Azure Service Bus, ensuring high throughput and reliability. * Implement and maintain asynchronous and background processing using Azure Functions and message\-driven patterns. * Lead data design and performance optimisation in Azure SQL / EF Core, including indexing strategies, query tuning, and transactional consistency. * Establish and promote engineering standards, reusable patterns, and shared components across services. * Apply advanced security practices using Azure Entra ID (OAuth2/OIDC, JWT) and secure\-by\-design principles. * Contribute to and improve CI/CD pipelines (Azure DevOps) and containerised deployments (Azure Container Apps). * Drive observability and production excellence using Application Insights and OpenTelemetry, defining logs, metrics, and traces. * Lead troubleshooting and incident resolution, performing root\-cause analysis in distributed systems. * Collaborate across teams, influencing technical direction and ensuring alignment with architectural standards. * Actively contribute to design reviews, architecture discussions, and knowledge sharing, raising the overall engineering bar. **Required Skills and Qualifications:** * Expert\-level experience with C\# and .NET (preferably .NET 8/9, ASP.NET Core) in production environments * Strong experience designing and operating distributed systems and microservices architectures * Deep understanding of event\-driven systems (Azure Service Bus or similar) and asynchronous processing * Advanced knowledge of Azure SQL and Entity Framework Core, including performance tuning and data modelling * Strong experience with Clean Architecture, CQRS, and domain\-driven design (DDD) * Solid understanding of concurrency, threading, memory management, and performance optimisation in .NET * Experience with containerisation (Docker) and cloud\-native deployments * Hands\-on experience with CI/CD (Azure DevOps) and modern DevOps practices * Strong experience with observability (Application Insights, OpenTelemetry) and production diagnostics * Proven ability to debug complex distributed systems and resolve performance issues * Strong communication skills and ability to influence technical decisions * Advanced English * Proactive ownership of complex problems and commitment to continuous improvement. * Strong communication skills with both technical and non\-technical stakeholders. * Ability to navigate ambiguity and make pragmatic technical decisions. * Collaborative mindset with a focus on raising team standards and shared outcomes. * Resilient and adaptable in high\-scale, production\-critical environments. **Nice\-to\-have Skills:** * Experience working across modern microservices and legacy .NET systems. **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.****