Mid/Senior Fullstack Developer (.NET/Javascript/Typescript), Brazil

We are **tech transformation** specialists, uniting human expertise with AI to create scalable tech solutions. With over 7\.400 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. At CI\&T, we are seeking a highly skilled and motivated Mid/Senior Fullstack Developer (.NET/Javascript/Typescript) to join our team in Brazil. You will contribute to an innovative project in a collaborative, innovative, transforming, and multicultural environment. **Position Overview: As a Mid/Senior Fullstack Developer, you will drive the design and development of robust applications by leveraging the Microsoft .NET stack alongside modern JavaScript frameworks. You’ll collaborate closely with product owners, QA engineers, and fellow developers, ensuring that our solutions not only meet but exceed client expectations. Your expertise will help shape the future of our platform in an agile and transformative setting. **Key Responsibilities** * Design, build, and maintain robust applications using the Microsoft .NET stack (C\#, ASP.NET) * Develop dynamic, modern front\-end interfaces using JavaScript and associated frameworks/libraries * Write efficient, scalable SQL Server queries, functions, and stored procedures supporting both on\-prem and Azure PaaS * Leverage OpenSearch as part of our backend architecture for search and data analytics * Optimize and troubleshoot full\-stack performance, scalability, and system reliability issues * Conduct and participate in code reviews, ensuring adherence to clean code practices * Collaborate with QA and product teams to understand requirements and deliver complete, tested features **Must\-Have Skills** * Proven track professional experience as a software developer * Strong expertise in: * C\#, ASP.NET, and .NET Core * Modern JavaScript (e.g., Angular, React, or Vue) * SQL Server (including query optimization and performance tuning) * OpenSearch/Elasticsearch * Git (branching, pull requests, merge conflict resolution) * Technical SEO knowledge covering canonical URLs, dynamic content rendering, and structured data optimization * Deep understanding of full\-stack applications and troubleshooting production issues * Proven experience optimizing performance and identifying system bottlenecks * Excellent communication skills—both verbal and written * Ability to work autonomously and collaboratively in a fast\-paced, agile environment **Nice\-to\-have Skills** * Familiarity with Azure PaaS services such as App Services, Azure Functions, and Storage Accounts * Experience with Azure DevOps (pipelines, repositories) * Working knowledge of geospatial data in PostgreSQL/PostGIS or similar Join CI\&T, where we are driven by Collaboration, Innovation \& Transformation. In our fast\-evolving landscape, your contributions will not only enhance our projects but also pave the way for breakthroughs powered by Artificial Intelligence. Together, let’s shape a bright future. **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. 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.******