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Hi, I’m Leonardo da Costa, a frontend developer with 7+ years of experience specializing in React.js and Next.js. I build responsive, scalable web applications and have a track record of optimizing performance, including reducing latency by more than 75% using Cloudflare Workers and modern frontend workflows. I enjoy translating UI/UX designs into reusable components and delivering end-to-end deployments with clean, testable code in JavaScript (ES6+) and TypeScript, complemented by Tailwind CSS. I’m proficient in building on headless WordPress stacks (Faust.js, ACF Flexible Content) and collaborating across design, product, and engineering teams to create maintainable component libraries and accessible interfaces (WCAG). I value performance, accessibility, and cross-functional knowledge sharing, and I’ve led frontend initiatives from concept through deployment.…Hi, I’m Leonardo da Costa, a frontend developer with 7+ years of experience specializing in React.js and Next.js. I build responsive, scalable web applications and have a track record of optimizing performance, including reducing latency by more than 75% using Cloudflare Workers and modern frontend workflows. I enjoy translating UI/UX designs into reusable components and delivering end-to-end deployments with clean, testable code in JavaScript (ES6+) and TypeScript, complemented by Tailwind CSS. I’m proficient in building on headless WordPress stacks (Faust.js, ACF Flexible Content) and collaborating across design, product, and engineering teams to create maintainable component libraries and accessible interfaces (WCAG). I value performance, accessibility, and cross-functional knowledge sharing, and I’ve led frontend initiatives from concept through deployment.

Leonardo da Costa

Web Developer, Front-End Developer, Programmer, +2

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Hi, I’m Leonardo da Costa, a frontend developer with 7+ years of experience specializing in React.js and Next.js. I build responsive, scalable web applications and have a track record of optimizing performance, including reducing latency by more than 75% using Cloudflare Workers and modern frontend workflows. I enjoy translating UI/UX designs into reusable components and delivering end-to-end deployments with clean, testable code in JavaScript (ES6+) and TypeScript, complemented by Tailwind CSS. I’m proficient in building on headless WordPress stacks (Faust.js, ACF Flexible Content) and collaborating across design, product, and engineering teams to create maintainable component libraries and accessible interfaces (WCAG). I value performance, accessibility, and cross-functional knowledge sharing, and I’ve led frontend initiatives from concept through deployment.…Hi, I’m Leonardo da Costa, a frontend developer with 7+ years of experience specializing in React.js and Next.js. I build responsive, scalable web applications and have a track record of optimizing performance, including reducing latency by more than 75% using Cloudflare Workers and modern frontend workflows. I enjoy translating UI/UX designs into reusable components and delivering end-to-end deployments with clean, testable code in JavaScript (ES6+) and TypeScript, complemented by Tailwind CSS. I’m proficient in building on headless WordPress stacks (Faust.js, ACF Flexible Content) and collaborating across design, product, and engineering teams to create maintainable component libraries and accessible interfaces (WCAG). I value performance, accessibility, and cross-functional knowledge sharing, and I’ve led frontend initiatives from concept through deployment.

Available to hire

Hi, I’m Leonardo da Costa, a frontend developer with 7+ years of experience specializing in React.js and Next.js. I build responsive, scalable web applications and have a track record of optimizing performance, including reducing latency by more than 75% using Cloudflare Workers and modern frontend workflows. I enjoy translating UI/UX designs into reusable components and delivering end-to-end deployments with clean, testable code in JavaScript (ES6+) and TypeScript, complemented by Tailwind CSS.

I’m proficient in building on headless WordPress stacks (Faust.js, ACF Flexible Content) and collaborating across design, product, and engineering teams to create maintainable component libraries and accessible interfaces (WCAG). I value performance, accessibility, and cross-functional knowledge sharing, and I’ve led frontend initiatives from concept through deployment.

Skills

Experience Level

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Work Experience

Frontend Developer at Concentrix

October 1, 2022 - Present

Led development of a production AI chat widget on Cloudflare Workers, replacing a failed vendor solution and reducing latency from ~12 seconds to under 3 seconds. Built an internal lead-generation tool that ingests raw post-event data, auto-generates structured contact profiles via Claude API and Vercel AI SDK, and surfaces enriched leads to sales. Implemented frontend on Next.js with a headless WordPress stack (Faust.js, ACF Flexible Content) and Tailwind CSS, deploying to Cloudflare Workers. Published 500+ Elementor landing pages and posts; authored SOPs to improve team infrastructure and cross-functional knowledge sharing. Rebuilt concentrix.com across two iterations, delivering a modular WordPress Elementor theme while maintaining WCAG accessibility. Developed and maintained an internal React component library (Tsup, Tailwind, Radix UI) with Jest tests.

Web Developer at J.M. Field Marketing and Fulfillment

September 1, 2018 - September 1, 2022

Built 5+ eCommerce storefronts using WooCommerce and custom Shopify Liquid themes; maintained and optimized 30+ client websites monthly, performing performance audits, analytics, and SEO to drive traffic and engagement. Delivered cross-browser, device-responsive front-end builds with WCAG accessibility, focusing on performance optimization and user experience.