Jean Souza

Senior Frontend Engineer

15+ years building production web interfaces, from the jQuery era through React 19, Next.js 16 App Router, and React Server Components, specializing in React, Next.js, and TypeScript. Across healthtech, e-commerce, and telecom I've shipped design systems, micro-frontends at scale, and open source libraries, including 92% test coverage at Luizalabs and a 67% build-time reduction at Zydon. At the intersection of frontend and infrastructure, I run a production homelab with 50+ Docker containers, blue/green deployments, and Python automation: three years of real ops, not side projects. C2-certified English (EF SET 82/100) and active daily use of AI assistants (Claude Code, Windsurf) as a core part of my engineering workflow.

Experience

1. October 2024 – March 2026

   Senior Front-End Engineer (React/Next.js/TypeScript)

   @ Zydon · Uberlândia, Brazil

   • Built the testing suite from scratch across a multi-repo micro-frontend environment: 70% total coverage where none had existed before.
   • CI pipeline optimized: build time dropped from 1 hour to 20 minutes (67% reduction), with observability added through log and metric instrumentation.
   • Executed critical state management refactoring using Redux and Next.js custom hooks from Figma specs, lowering client-side memory footprint and optimizing the portal's Core Web Vitals indices.
   • Migrated core portal pages to Next.js App Router with React Server Components and SSR, cutting client-side JavaScript payload and improving LCP and INP scores across the product.

2. January 2024 – August 2024

   Senior Front-End Engineer (TypeScript)

   @ Mutant · São Paulo, Brazil

   • Led the team in building a Web Components library (Lit) for Vivo, one of Brazil's largest telcos, fully interoperable across Angular and React in a micro-frontend architecture with no per-framework rewrites needed.
   • 100% of components shipped WCAG 2.1 AA-compliant, making the entire library accessible to assistive technologies and reducing the client's legal exposure.
   • Lerna monorepo structured so each squad imported only what it needed, cutting bundle size and reducing coupling between teams.

3. August 2022 – October 2023

   Senior Front-End Engineer (React)

   @ Runrun.it · São Paulo, Brazil

   • Built the bulk-actions tool used across multiple critical flows of the main product, with React and custom hooks abstracting the legacy Backbone integration so new engineers didn't need to learn the old stack.
   • Defined the incremental Backbone → React migration strategy with Webpack and per-route code-splitting: new React features shipped without a full rewrite, preserving existing user flows and improving Lighthouse performance scores.
   • Code quality standards established (ESLint, review guidelines, hook architecture) that the team kept using after I left.

4. January 2020 – June 2022

   Senior Front-End Engineer (React/TypeScript)

   @ Luizalabs · Uberlândia, Brazil

   • Collaboratively helped the team achieve 92% test coverage with Jest + RTL on the main project: the milestone that unlocked the company's continuous delivery pipeline and became an internal quality benchmark.
   • Introduced unit tests and an automated deployment pipeline to a legacy project with zero coverage, shrinking release times from 2 days (manual) to just 1 hour with zero regressions.
   • High-scale micro-frontend applications architected and integrated into Magalu's unified platform, establishing client-side orchestration standards, secure state sharing, and automated release workflows via Git Flow and Conventional Commits.

5. August 2017 – January 2020

   Full-Stack Engineer (Vue/TypeScript/Node)

   @ Vitta · Uberlândia, Brazil

   • Created and led Vi-Ui, an open source Vue component library that became the foundation of the company's design system.
   • Internal design system developed to unify visual language across all company applications: less UI inconsistency, faster feature delivery.
   • Technical optimization of Vitta's corporate portal for search engines (SEO) and Core Web Vitals, implementing Server-Side Rendering (SSR) in Vue, strict HTML semantics, and structured data, resulting in a substantial increase in organic traffic.

6. April 2012 – July 2017

   Senior Front-End Engineer

   @ LuxControl Automação Residencial · Uberlândia, Brazil

   • 5 years leading front-end development for an embedded home automation system: air-gapped, strict performance constraints, no room for deployment mistakes.
   • React and REST API consumption introduced to the legacy system without interrupting service for customers already running in production.
   • Optimized LuxControl's corporate website focusing on SEO and Core Web Vitals indices (LCP, FID, CLS), boosting Google Lighthouse scores above 95% and expanding the brand's digital presence.

7. September 2011 – April 2012

   Full-Stack Developer (PHP/MySQL)

   @ Bockz

   • Full-stack development using PHP and MySQL, including deep WordPress theme and plugin customization. Heavy focus on on-page SEO, semantic structure, and page speed for corporate sites.

8. January 2011 – August 2011

   Full-Stack Developer

   @ OpenK Tecnologia

   • Corporate portals built with Java (JSP/Servlets) and PHP, integrating responsive layouts in HTML5/CSS3 with web accessibility and basic technical SEO best practices.

9. November 2008 – February 2010

   Interface Programmer

   @ Webroom Soluções Interativas

   • Dynamic interfaces using jQuery and Vanilla JavaScript at a digital agency. Focused on page load performance, cross-browser consistency, and on-page SEO for e-commerce and corporate sites.

10. April 2008 – November 2008

    Web Designer

    @ Lalli Bureau

    • First contact with IT: UI design using Photoshop and Fireworks, print graphic design and layout for magazines and catalogs. Hand-coded layouts to semantic, accessible, SEO-optimized HTML/CSS.

Education

Languages

Portuguese (native) · English C2 (EF SET 82/100)