1-day current streak·82-day longest streak
👋 Hi My name is Leonardo Maldonado. Software engineer from Brazil, based in Valencia, Spain. 7+ years building for the web — from early-stage startups to international product companies. Creator…
👋 Hi
My name is Leonardo Maldonado. Software engineer from Brazil, based in Valencia, Spain. 7+ years building for the web — from early-stage startups to international product companies.
Creator of 33 JavaScript Concepts — helped thousands of developers to learn JavaScript, translated into 40+ languages, recognized by GitHub as a top open-source project of 2018.
About me
- For four and a half years, the sole frontend engineer on Spaceship domain search at Namecheap — helped the platform sell 3M+ domains.
- Written 100+ technical articles on JavaScript, TypeScript, React, and Node.js for LogRocket and Progress.
- I build things across languages — JavaScript, TypeScript, Go, Rust — because shipping is how I learn.
Projects
- 33-js-concepts — 33 JavaScript concepts every developer should know. 66K+ stars and translated into 40+ languages by the community.
- Shopwyse — An ERP I built for retailers who need POS, inventory, CRM, and financial reporting under one roof. TanStack Start, Elysia, PostgreSQL.
- Polyglot — An AI writing assistant that interviews you first, then drafts content in your voice from different angles.
- Otis Finance — A stock market API for real-time prices, SEC filings, earnings, and financials.
- gone — I wanted a dead link detector that was actually fast, so I wrote one in Go. Concurrent, has a TUI, and works in CI.
- betterhook — A git hooks manager I built in Rust because existing ones don't handle worktrees or parallel agents well. DAG scheduling, blake3 caching, Tokio under the hood.
- rust-skills — 179 rules I wrote so AI coding agents stop guessing when they write Rust.
Writing
- LogRocket Blog — React, TypeScript, frontend architecture.
- Progress / Telerik Blog — React, Node.js, modern JavaScript.
Get in touch
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33-js-concepts ★ PINNED
📜 33 JavaScript concepts every developer should know.
JavaScript ★ 66k 1mo agoExplain → -
gone ★ PINNED
Fast, concurrent dead link detector for files.
Go ★ 1 1mo agoExplain → -
rust-skills ★ PINNED
A collection of 265 rules across 26 categories that AI coding agents can use to write idiomatic, fast, and safe Rust.
Python ★ 303 22d agoExplain → -
betterhook ★ PINNED
Fast, worktree-native git hooks manager built for parallel AI coding agents.
Rust ★ 2 2mo agoExplain → -
awesome-fsm
🤖 A curated list of awesome resources related to finite state machines and statecharts.
JavaScript ★ 435 1y agoExplain → -
react-bolt
⚡ The most simple & robust boilerplate for your React projects.
JavaScript ★ 324 3y agoExplain → -
graphql-mongodb-server
A GraphQL MongoDB server.
JavaScript ★ 254 3y agoExplain → -
roover
🐱 A lightweight audio library for React apps.
TypeScript ★ 96 2y agoExplain → -
react-google-static
🌍 A React wrapper for Google Static Maps API.
TypeScript ★ 47 2y agoExplain → -
You-Dont-Know-JS ⑂
A book series on JavaScript. @YDKJS on twitter.
★ 30 3y agoExplain → -
graphql-101
GraphQL Series final repo.
JavaScript ★ 18 3y agoExplain → -
awesome-interview-questions ⑂
:octocat: A curated awesome list of lists of interview questions. Feel free to contribute! :mortar_board:
★ 16 3y agoExplain → -
dev-app
A developer app made with React, Redux, Express, MongoDB.
JavaScript ★ 13 3y agoExplain → -
slatt
🐍 Another form library for React? Oh, please!
TypeScript ★ 11 2y agoExplain → -
website
My website.
JavaScript ★ 10 1mo agoExplain → -
cactus
🌵 Cactus, a task board made with React Hooks.
JavaScript ★ 10 3y agoExplain → -
Front-End-Performance-Checklist ⑂
🎮 The only Front-End Performance Checklist that runs faster than the others
★ 8 7y agoExplain → -
chuck-cli
A simple Chuck Norris Jokes CLI.
JavaScript ★ 8 8y agoExplain → -
blog-with-nextjs
A simple blog built with Next.js
TypeScript ★ 8 5y agoExplain → -
data-structure-and-algorithms-with-ES6 ⑂
Data Structures and Algorithms using ES6
JavaScript ★ 7 8y agoExplain → -
awesome ⑂
:sunglasses: Curated list of awesome lists
★ 7 7y agoExplain → -
free-programming-books ⑂
:books: Freely available programming books
★ 6 9y agoExplain → -
awesome-redux ⑂
Awesome list of Redux examples and middlewares
★ 6 8y agoExplain → -
graphql-relay-compatible
No description.
TypeScript ★ 6 5y agoExplain → -
the-book-of-secret-knowledge ⑂
A collection of inspiring lists, manuals, cheatsheets, blogs, hacks, one-liners, cli/web tools and more.
★ 6 3y agoExplain → -
weather
🌦 Weather app
TypeScript ★ 5 5y agoExplain → -
design-blocks ⑂
A set of 170+ Bootstrap based design blocks ready to be used to create clean modern websites.
HTML ★ 4 7y agoExplain → -
caption ⑂
Get Caption, start watching.
JavaScript ★ 4 7y agoExplain → -
cantus
🍬 A website built with CSS Grid Layout & Sass only.
CSS ★ 4 4y agoExplain → -
budget-app
💰 A budget app with JavaScript.
JavaScript ★ 4 4y agoExplain → -
midday ⑂
Run your business smarter.
★ 4 2y agoExplain → -
js-stack-from-scratch ⑂
🛠️⚡ Step-by-step tutorial to build a modern JavaScript stack.
JavaScript ★ 3 8y agoExplain → -
docz ⑂
✍🏻It has never been so easy to document your things!
TypeScript ★ 2 7y agoExplain → -
curso-javascript-ninja ⑂
Curso Javascript Ninja
JavaScript ★ 2 8y agoExplain → -
react-redux-links ⑂
Curated tutorial and resource links I've collected on React, Redux, ES6, and more
★ 2 8y agoExplain → -
empresas-que-usam-react-no-brasil ⑂
Repositório que mostra empresas e projetos que utilizam React no Brasil
★ 2 7y agoExplain → -
relay-modern-course ⑂
Relay Modern Course
TypeScript ★ 2 7y agoExplain → -
spotify-graphql
No description.
TypeScript ★ 2 5y agoExplain → -
simple-todo
🎃 A simple todo made with JavaScript.
CSS ★ 2 4y agoExplain → -
react-pagination ⑂
Created with StackBlitz ⚡️
★ 2 3y agoExplain → -
xstate ⑂
State machines and statecharts for the modern web.
TypeScript ★ 2 3y agoExplain → -
radix ⑂
Design System and Component Library for Modulz
TypeScript ★ 2 3y agoExplain → -
jest-dom ⑂
:owl: Custom jest matchers to test the state of the DOM
JavaScript ★ 2 3y agoExplain → -
taxonomy ⑂
An open source application built using the new router, server components and everything new in Next.js 13.
TypeScript ★ 2 3y agoExplain → -
tanstack-better-auth-session
No description.
TypeScript ★ 2 8mo agoExplain → -
leonardomso
No description.
★ 1 16d agoExplain → -
react ⑂
A declarative, efficient, and flexible JavaScript library for building user interfaces.
JavaScript ★ 1 8y agoExplain → -
homebrew-tap
No description.
Ruby ★ 1 1mo agoExplain → -
redux ⑂
Predictable state container for JavaScript apps
JavaScript ★ 1 8y agoExplain → -
tableless ⑂
O site do Tableless em Hugo. Mais leve, impossível.
HTML ★ 1 8y agoExplain → -
react-universally ⑂
A starter kit for universal react applications.
JavaScript ★ 1 8y agoExplain → -
node ⑂
Node.js JavaScript runtime :sparkles::turtle::rocket::sparkles:
JavaScript ★ 1 8y agoExplain → -
react-testing-library-todo-example ⑂
Sample Todo widget to help understand testing with react-testing-library
JavaScript ★ 1 7y agoExplain → -
react-redux-boilerplate ⑂
A minimal React-Redux boilerplate with all the best practices
JavaScript ★ 1 8y agoExplain → -
podcast-search ⑂
This API serves to search podcasts and informations about it.
★ 1 8y agoExplain → -
relay ⑂
Relay is a JavaScript framework for building data-driven React applications.
JavaScript ★ 1 8y agoExplain → -
react-testing-library ⑂
🐐 Simple and complete React DOM testing utilities that encourage good testing practices.
JavaScript ★ 1 8y agoExplain → -
react-slingshot ⑂
React + Redux starter kit / boilerplate with Babel, hot reloading, testing, linting and a working example app built in
JavaScript ★ 1 8y agoExplain → -
graphql ⑂
GraphQL is a query language and execution engine tied to any backend service.
Shell ★ 1 8y agoExplain → -
react-webpack-boilerplate ⑂
Minimalistic ES6+ React boilerplate with Hot Reloading using Webpack 4 and Babel 7
JavaScript ★ 1 7y agoExplain → -
graphpack ⑂
☄️ A minimalistic zero-config GraphQL server.
JavaScript ★ 1 7y agoExplain → -
sped-nfe ⑂
API para geração e comunicação das NFe com as SEFAZ autorizadoras
★ 1 1y agoExplain → -
backend-engineering-course-go-chi
First couse building a REST API using Go.
Go ★ 1 7mo agoExplain → -
claude-task-master ⑂
An AI-powered task-management system you can drop into Cursor, Lovable, Windsurf, Roo, and others.
JavaScript ★ 1 6mo agoExplain → -
sequin ⑂
Postgres change data capture to streams, queues, and search indexes like Kafka, SQS, Elasticsearch, HTTP endpoints, and more
★ 1 4mo agoExplain → -
sped-cte ⑂
API para geração e comunicação das CTe com as SEFAZ autorizadoras
PHP ★ 1 4mo agoExplain → -
better-auth ⑂
The most comprehensive authentication framework
★ 1 2mo agoExplain → -
paperclip ⑂
Open-source orchestration for zero-human companies
★ 0 3mo agoExplain →
No repos match these filters.