Senior Fullstack Developer (.NET/JavaScript/React)

Location: Brazil; remote homeoffice

Company

CI&T is a technology transformation company delivering AI deployment, application modernization, data and AI, martech, and business strategy solutions for large enterprises.

What you will do

• Design, build, test, and maintain scalable, secure, and resilient fullstack applications with .NET Core and React.
• Address frontend and backend security vulnerabilities using secure coding standards and OWASP principles.
• Implement architectural guidelines in clean, maintainable, well-tested code and contribute technical insights to design discussions.
• Monitor, troubleshoot, and optimize application performance, reliability, and backend/frontend interactions.
• Use Claude Code, AI tools, and agentic workflows to accelerate development, refactoring, testing, and delivery.
• Drive test coverage and CI/CD quality, conduct code reviews, and mentor junior and mid-level developers.

Requirements

• Senior-level experience in fullstack web application development.
• Proficiency with .NET Core and C#, with familiarity with ASP.NET.
• Strong hands-on experience with JavaScript, TypeScript, and React.
• Experience using Claude Code through terminal, IDE, and GitHub integrations.
• Practical experience applying AI agents and AI-driven workflows across the software development life cycle.
• Understanding of SOLID, DRY, microservices, and monolithic design patterns.
• Experience with relational and non-relational databases, including SQL Server, PostgreSQL, or MySQL, query optimization, and schema design.
• Familiarity with AWS, containerization, RESTful API design, Git, and automated CI/CD pipelines.
• Strong analytical, problem-solving, written and verbal communication, collaboration, ownership, adaptability, and continuous-learning skills.
• Ability to diagnose and resolve complex technical issues in production environments and connect product and engineering discussions.

Culture & Benefits

• Remote homeoffice work in Brazil.
• Collaborative, team-oriented environment focused on continuous learning.
• Opportunities to use AI technologies to improve development efficiency and code quality.
• Company benefits are provided through CI&T's careers program.

Hiring process

• Applicants are expected to present an assessment during the selection process.
• Support is available for candidates who do not yet have the assessment, including assistance with obtaining it.