I build fast web apps

a drawing of marcelo Welcome! I am a senior software engineer in Brazil with 8+ years across frontend and full-stack. I specialize in web performance and in shipping apps end to end. Day to day I work with JavaScript and TypeScript (Vue, React, Svelte), Core Web Vitals, and Go.

In my time at Upwork I led a cross-team effort that improved Core Web Vitals by ~30% company-wide, and built the monitoring that kept them from regressing at the time.

This past year I have been building my own apps, like Novaboard, a pixel-art editor that has grown organically to ~18k monthly visitors.

I am open to remote senior roles (US/EU hours), web-performance consulting, and freelance projects. Email me at marcelo@lotuz.dev.

GitHub · LinkedIn · X · CV (PDF)

Projects

Novaboard

a free pixel art and animation studio in the browser, with ~18k monthly visitors

Moneykeep

a personal finance app built end-to-end with Go, SQLite and TypeScript

Quacktory

a chill factory game about building a giant golden duck

jsminify

a JavaScript minifier written in C on top of tree-sitter

CustomItems

a Minecraft plugin to add your own custom items, the simple way

BrasaScript

a Portuguese dialect of JavaScript

Opensanca

my contributions to the São Carlos developer community (2019–2025)

Prank

a worms like game built in HTML5

Agrade

A college class tracker

Sokobox

a sokoban clone build in C

Writing

Note taking

 Dec 6, 2020

how I plan to turn years of paper notes into a knowledge base

Git course

 Aug 4, 2020

I am going to give an online git course

Notes

Javascript Modules

 Jul 2, 2021

IIFE, AMD, CommonJS and ES modules, and why the differences still matter