Sr. Developer FullStack (.Net/React)

At CI&T, we help large enterprises transform the potential of AI into real business impact with AI Deployment, AI-native execution, and tech-integrated business solutions.

With 30 years of experience in technological transformation, we accelerate innovation with expertise in Agentic SDLC, Application modernization, Data & AI, Martech and Business strategy.

We are 8,000 CI&Ters across more than 25 countries, collaborating to build solutions with real impact. AI is already part of how we work, evolve, and innovate every day.

We are looking for a Fullstack Developer with a strong focus on frontend development (70%) and solid backend skills (30%), working in a modern tech stack built on .NET 8, C#, and React. You will build high-quality, scalable, and maintainable features across the full stack, collaborating closely with product, design, and engineering teams.

Develop and maintain responsive, performant, and accessible user interfaces using React

Implement reusable components following best practices for scalability and maintainability

Collaborate with UX/UI designers to translate designs into functional features

Ensure cross-browser compatibility and performance optimization

Write unit and integration tests for frontend components

Develop and maintain RESTful APIs and services using .NET 8 and C#

Implement business logic using the Mediator pattern (MediatR) for clean and decoupled architecture

Use AutoMapper for efficient object-to-object mapping

Implement asynchronous messaging with Rebus and Azure Service Bus

Contribute to database design and queries using PostgreSQL and MongoDB

Write unit tests using xUnit and generate realistic test data with Faker (Bogus)

Create test doubles and mocks using NSubstitute

Participate in code reviews to uphold code quality standards

Work with Azure DevOps for project management, version control, and pipelines

Follow GitFlow branching strategy for organized and release-oriented development

Contribute to Azure Pipelines (CI/CD) using YAML-based configurations

Solid experience with React (hooks, context, state management)

Proficiency in JavaScript / TypeScript

Experience with component-driven development and modern frontend architecture patterns

Experience with .NET 8 and C# for backend development

Familiarity with MediatR, AutoMapper, and clean architecture principles

Experience with messaging/queueing systems (Rebus, Azure Service Bus, or equivalent)

Experience with PostgreSQL — relational modeling and query optimization

Experience with MongoDB — document-based modeling and aggregation

Proficiency with Entity Framework Core (EF Core)

xUnit for unit and integration testing

NSubstitute for mocking and test doubles

Faker / Bogus for realistic test data generation

Azure DevOps, Git, GitFlow, Azure Pipelines, Azure Service Bus

Knowledge of CQRS combined with MediatR

Familiarity with Docker and containerization

Exposure to Azure cloud services (App Services, Functions)

Understanding of Domain-Driven Design (DDD) principles

Experience with micro-frontend architecture

#LI-AM2

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.