Summary: We are seeking a Tech Lead Developer with front-end expertise to drive UI engineering, architecture, and design system leadership for a major American investment client. Highlights: 1. Lead UI Engineering & Architecture for innovative projects 2. Own and evolve a Design System with reusable components 3. Work with cutting-edge front-end technologies and micro-frontends We are **tech transformation** specialists, uniting human expertise with AI to create scalable tech solutions. With over 8,000 CI\&Ters around the world, we’ve built partnerships with more than 1,000 clients during our 30 years of history. Artificial Intelligence is our reality. We are looking for a **Tech Lead Developer** with experience in front\-end development to join our team on an innovative and challenging project for a major American investment client. **Responsibilities:*****UI Engineering \& Architecture*** Build and maintain front‑end apps using React, Angular, or Lit. Architect micro‑frontends using Module Federation and modern build tools (Webpack, Vite, Rollup). Establish scalable patterns for routing, composition, shared dependencies, and versioning. Optimize performance (bundle splitting, caching, lazy loading, profiling). ***Design System Leadership*** Own and evolve a Design System with reusable framework agnostic components and design tokens. Support theming/branding across applications and micro‑frontends. Define component standards, contribution guidelines, API patterns, and documentation. Ensure accessibility (WCAG/ARIA), responsiveness, and cross‑browser compatibility. Partner with UX for design\-to\-code alignment. **Requirements for this challenge:** Advanced English for communicating with the client and the team. Previous experience as a fullstack tech lead focused on front\-end development. Strong React, JavaScript (ES6\+), HTML/CSS, responsive design. Hands\-on with Lit, Preact, Vite, Rollup, Webpack, and module systems. State management (Zustand, Redux, Context API). Testing (Jest, React Testing Library). Experience with design systems and atomic design. Ability to meet AAA accessibility standards. REST API integration. CI/CD and Github experience. Micro\-frontend architecture and performance optimization. Strong grasp of security, performance, and accessibility best practices. **Nice to have:** Familiarity with Docker, caching strategies, and configuration management. Strong communication and leadership skills. Ability to drive governance and standards for Design Systems and micro‑frontends. Experience with monorepos and semantic versioning. Component library integration experience. **Important: Availability to work at the Campinas base 3x per week (Tue,Wed and Thu).** \#LI\-AG4 \#Midsenior **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.