[Job-32277] Senior FullStack Developer (.NET/Javascript/React)
Senior fullstack developer at CI&T building, securing, and optimizing web applications with a .NET Core (C#) backend and React/TypeScript frontend. Day-to-day covers feature delivery, testing and CI/CD, code reviews and mentoring, plus heavy use of AI tools like Claude Code and agentic workflows to speed up development.
- Compensation
- Not disclosed
- Location
- Brazil
- Work setup
- Remote
- Seniority
- Senior
- Employment
- Not specified
- Experience
- Not specified
- Category
- Fullstack
- Posted
Skills
Must have
- Proficient in using Claude Code via terminal, IDE, and GitHub integrations
- Practical experience applying AI agents and AI-driven workflows across the SDLC
- Proven backend development experience with deep expertise in .NET Core (C#) and familiarity with ASP.NET
- Strong hands-on proficiency in JavaScript, TypeScript, and modern frontend frameworks like React
- Solid understanding of SOLID, DRY, and microservices/monolithic design patterns
- Experience with relational and non-relational databases (SQL Server, PostgreSQL, MySQL), query optimization, and schema design
- Familiarity with cloud platforms (especially AWS), containerization, RESTful API design, Git, and CI/CD pipelines
- Drive test coverage (unit, integration, end-to-end) and code quality standards
- Adherence to secure coding standards and OWASP principles
- Soft skills: proactive ownership, critical thinking, adaptability, problem solving, and strong communication
Full description
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.
Job Overview:
We are on the lookout for a passionate and experienced Senior Fullstack Developer to join our engineering team. The ideal candidate will have a strong background in web application development—specifically with .NET Core—and the flexibility and eagerness to adapt to and learn new technologies, including legacy ASP.NET and modern JavaScript frameworks. Additionally, a solid understanding of frontend engineering using React is essential to build, maintain, and evolve high-performance user interfaces.
Key Responsibilities:
- Feature Engineering & Delivery: Design, build, test, and maintain scalable, secure, and resilient fullstack applications using .NET Core and React.
- Security & Best Practices: Actively address security vulnerabilities across both frontend and backend codebases, adhering to modern secure coding standards and OWASP principles.
- Architecture Implementation: Translate architectural guidelines into clean, maintainable, and well-tested code, contributing actionable technical insights to team design discussions.
- Performance Optimization: Continuously monitor, troubleshoot, and optimize application performance, reliability, and backend/frontend interactions.
- AI Tooling & Developer Velocity: Utilize AI tools and agentic workflows (e.g., Claude Code) to accelerate feature delivery, cross-file refactoring, and automated testing.
- Quality & Testing Ownership: Drive test coverage (unit, integration, end-to-end) and enforce robust code quality and CI/CD standards within the development pipeline.
- Team Leadership & Mentorship: Conduct thorough peer code reviews, mentor junior and mid-level developers, and foster a collaborative, continuous-learning culture.
Technical Skills:
- Claude Code Environment Experience: Proficient in using Claude Code via terminal, IDE, and GitHub integrations to accelerate codebase onboarding, cross-file refactoring, and feature delivery.
- Agentic SDLC Experience: Practical experience applying AI agents and AI-driven workflows across the software development life cycle.
- Backend Mastery: Proven experience in backend development with deep expertise in .NET Core (C#) and familiarity with ASP.NET.