We’re looking for a Senior .NET Developer to maintain and evolve a set of web .NET applications, with a strong focus on modernizing authentication/authorization flows and migrating to newer .NET Core versions. The frontend is built with React.

Responsibilities: Maintain and improve existing ASP.NET / .NET Core web apps with a React frontend. Redesign and implement modern authN/authZ (e.g. OAuth2/OIDC, JWT, identity providers). Plan and execute .NET Core upgrades. Work with AWS, MySQL, PostgreSQL, and multiple external integrations. Use Bitbucket, CI/CD, and Playwright tests as part of the delivery workflow. Collaborate with stakeholders to discuss and prioritize tasks and clarify requirements (in English).

Requirements: 5+ years of experience with .NET (C#) and web development. Proven experience with auth flows and .NET version migrations. Experience with React in production environments. Experience with AWS, relational databases, and integrations with third-party APIs. Comfortable with Bitbucket/Git and automated testing (Playwright is a plus). Fluent English and strong communication/relationship skills.

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.