Medusa is a desktop that runs in the browser, and the CV and the projects are apps on it. This is the same content as text.
Kevin Zaracho
Frontend engineer · React · TypeScript
Mercedes, Buenos Aires, Argentina (UTC-3) · Remote
[email protected] · LinkedIn · GitHub
Summary
Frontend engineer with 6 years building React applications, the last three as the sole frontend developer of a B2B e-commerce integration platform serving 180+ active merchants. I own the entire application surface — architecture, design system, internationalization, testing and release — and I care about the parts that don't show: enforced module boundaries, dead-code budgets, and a codebase the next person can navigate.
Experience
Frontend engineer — Grow2on
Apr 2023 – Present · Remote
Sole frontend engineer on the Grow2on web application — the authenticated product used by 180+ active merchants to sync an ERP with MercadoLibre, TiendaNube and Shopify. Scope is the app itself; the public marketing site is owned by another team.
- Own the application frontend end to end: architecture, design system, state, i18n, testing and release. React 19, TypeScript, Vite, Mantine, TanStack Query, React Router.
- Migrated the codebase to Feature-Sliced Design and made it non-negotiable — layer boundaries are enforced in CI with
steiger, so architectural drift fails the build instead of accumulating in review. - Built an offline-tolerant data layer with TanStack Query persistence over IndexedDB, plus list virtualization for catalogs in the tens of thousands of rows.
- Shipped the product-detail feature: catalog and detail routes with filter and pagination state persisted in the URL via
nuqs, and a flow that links local products to live MercadoLibre listings. - Set up the internationalization pipeline end to end — Tolgee integration with push/pull sync and a custom script that splits translation bundles per feature slice.
- Established the testing baseline: Vitest, Testing Library and MSW for API mocking, with coverage reporting in CI.
- Built the project's internal tooling in TypeScript: release-metadata generation, icon and favicon pipeline, and translation splitting.
- Adopted the React Compiler and keep the dependency surface honest with
knip, Husky hooks and a strict ESLint 9 / Prettier setup. - Instrumented product analytics (Hotjar, Microsoft Clarity) and used the findings to argue for UX changes with data rather than opinion.
Freelance web developer
2020 – 2023 · Remote
- Built React SPAs and marketing sites for agencies and direct clients — HR platforms, ISP landing pages, e-commerce, browser extensions.
- Refactored inherited codebases for performance and maintainability.
- Ran the full cycle solo: scoping with non-technical clients, responsive and accessible implementation, third-party API integration, deploy.
Projects
Medusa
Web app · Personal
The page you are looking at is not a page with a desktop inside: it is a desktop. The CV and the projects are apps that run on it.
Written 100% in Rust with egui and compiled to WebAssembly. Every app runs in its own Web Worker with its own egui context, tessellates there, and sends the desktop ready-made triangles. If an app crashes, the desktop does not notice.
The terminal runs a small bash of its own — pipes, loops, functions, grep, sed, awk, jq and curl — and the wallpaper is a port of Aurelia, a WebGPU jellyfish simulation.
- One process per window, with a typed system-call interface instead of stringly-typed messages
- A virtual filesystem that survives reloads, with per-app permissions
- Window animations, frosted glass and theme fades done by the compositor, not by the apps
Rust, egui, WebAssembly, wgpu, WebGPU
Argentum Online Atlas Viewer
Web app · Open source
Web viewer for the complete world of Argentum Online, a 2002 Visual Basic 6 MMO. Reverse-engineered the original client's binary formats (.map, .inf, .ind, cp1252 .ini) into a normalized JSON pipeline, then rebuilt the rendering to match the original engine — color-key transparency, sprite anchoring, four-layer draw order.
Connected all 317 maps into a single navigable graph by inferring teleport links with a bidirectional BFS. Canvas2D renderer with lazy per-map loading, LRU sprite cache, continuous zoom across six orders of magnitude, and touch support.
TypeScript, Canvas2D, Vite, GitHub Actions · AGPL-3.0
Markwork
Web app · Open source
A markdown editor and viewer with no backend at all. The document is LZ-compressed into the URL fragment, so sharing a link shares the content — no database, no accounts, and because fragments never reach a server, nothing leaves the browser.
Dual editing modes (CodeMirror source view and Tiptap rich text) with sanitized rendering via DOMPurify.
React 19, TypeScript, Vite, Mantine · MIT
Overcore
Tool · Open source
Visual page builder and design-system editor for Mantine. Built it to a working product, then open-sourced it after concluding it had no market fit: Mantine developers already write components, and non-developers won't adopt a framework-specific tool.
TypeScript, React, Mantine
Simper
Game · Personal
Offline browser-based life-simulation game built on a custom ECS architecture.
TypeScript, React, React Three Fiber, Vite
Grow2on
Dashboard · Client work
The authenticated web application that 180+ merchants use to sync their ERP with MercadoLibre, TiendaNube and Shopify, and to manage their products and listings across marketplaces from a single dashboard.
Kevin is its sole frontend engineer: see the CV for what that covers.
- Marketplace API integration and real-time inventory
- Advanced search and filtering, with the state in the URL
- Offline-tolerant data layer over IndexedDB
React 19, TypeScript, Vite, Mantine, TanStack Query
Artefear
Portfolio · Client work
A website for a street artist of the same name. React Spring moves the hero image and Swiper drives the gallery sliders.
React, TypeScript, Tailwind CSS, React Spring, Swiper
Un-Level
Landing page · Client work
A landing page about NFTs and blockchain, built for a client from scratch on top of an existing design. Mobile first and responsive up to 1920 px, with Swiper for the sliders.
React, TypeScript, Tailwind CSS, Swiper
Superstoria
Social network · Client work
A website for readers and writers about curiosities, built on an existing design.
React on the front end, with React Router, React Icons, Tailwind CSS and Fontsource. On the back end, Strapi as a headless CMS served the API and the client, with PostgreSQL for the data and Cloudinary for the media.
Another developer changed the live site after the handover, and it has since gone offline.
React, JavaScript, Tailwind CSS, Strapi, PostgreSQL
Inter-fas
Landing page · Client work
A landing page for a company that provides wireless internet and fiber optics. Built from scratch from a design, with React and Tailwind CSS.
React, JavaScript, Tailwind CSS
Infocus
Landing page · Client work
The website of a company that recruits and selects staff for other companies.
React, JavaScript, Tailwind CSS, Vite, Swiper
Casitapp
Browser extension · Personal
A Chrome extension that gives the new tab page a clean, useful look. The clock, the background, the font and the shortcuts can all be customized.
Built with React, Tailwind CSS and date-fns; the backgrounds come from the Bing (through a proxy) and Unsplash APIs, and the fonts from Google Fonts.
React, Tailwind CSS, date-fns
Beatstore
E-commerce · Personal
The first site Kevin built almost entirely on his own: a music-production CV to show his projects, sell instrumentals and offer his services. No framework at all.
JavaScript
Skills
- Core: TypeScript, JavaScript, React 19, HTML, CSS/Sass
- Frontend: Mantine, TanStack Query, React Router, Vite, Framer Motion, nuqs, Next.js, React Three Fiber, Canvas2D
- Architecture and quality: Feature-Sliced Design, Vitest, Testing Library, MSW, ESLint, Prettier, Husky, Knip
- Backend and data: Node.js, Prisma, PostgreSQL, SQLite, REST, GraphQL
- Other: Git, Docker, Linux/VPS, GitHub Actions, i18n (Tolgee), Figma
Education
- Full-stack developer (MERN), certified — Coderhouse · 2020 – 2022
Languages
- Spanish: Native
- English: Professional working proficiency