[Job-32277] Senior FullStack Developer

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.
- Frontend Engineering: Strong hands-on proficiency in JavaScript, TypeScript, and modern frontend frameworks like React.
- Software Design: Solid understanding of core software development principles (SOLID, DRY) and microservices/monolithic design patterns.
- Data Management: Experience with relational and non-relational databases (e.g., SQL Server, PostgreSQL, MySQL) including query optimization and schema design.
- Cloud & DevOps: Familiarity with cloud computing platforms (especially AWS), containerization, RESTful API design, Git, and automated CI/CD pipelines. Soft

Skills:
Proactive Ownership: Demonstrates initiative by identifying challenges early, proposing pragmatic solutions, and taking end-to-end responsibility with minimal supervision.
- Critical Thinking: Questions underlying assumptions and analyzes problems from foundational concepts up, ensuring deep technical comprehension before taking action.
- Adaptability & Continuous Learning: Eagerness to learn new languages, frameworks, and engineering tools as technical demands evolve.
- Problem Solving: Strong analytical skills with a track record of diagnosing and resolving complex technical issues in production environments.
- Communication & Collaboration: Excellent written and verbal communication skills, with a team-oriented mindset and ability to bridge discussions between product and engineering.
- AI Enthusiasm: A genuine interest in leveraging AI technologies to enhance development efficiency and code quality. 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](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](https://docs.google.com/presentation/d/12BqYLIGeEyp9t0ZdF2b4bvnjFLza4E8fmbcowWeBlfk/edit?slide=id.g3a9cf52bf2b_0_0#slide=id.g3a9cf52bf2b_0_0)*[.](https://docs.google.com/presentation/d/12BqYLIGeEyp9t0ZdF2b4bvnjFLza4E8fmbcowWeBlfk/edit?slide=id.g3a9cf52bf2b_0_0#slide=id.g3a9cf52bf2b_0_0)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.