About
I'm Celso. I live in Curitiba, Brazil, and work as a product engineer at Salvy. In 2024 I went back to university, which means studying compilers the same month I'm arguing about MCP with my product team. I still haven't decided which one teaches me more.
Before I wrote software I collected fares on a city bus.
the name
It comes from the kernel. When the fast path misses, the code falls into the slowpath: asks for a new page, sleeps waiting on a lock, goes all the way to the disk. It's the boring path, and it's where things actually happen.
It's also the slow bus line, the one that stops everywhere. I was always assigned to the neighborhood routes, the long ones, and those were where the best conversations with passengers happened.
This is where I want to share the ideas and thoughts of an anxious mind that is learning to think slow.
things I've built
Almost everything here started from curiosity, not from need.
| diple | got tired of finding out late that a PR was waiting on me. became a native macOS app that lives in the notch |
| pollhttpd | an HTTP/1.1 server in C on top of poll(), no framework, no dependencies. wrote it to understand syscalls |
| solo_chess | played way too much chess.com and wanted a version with no distractions, keyboard only |
| rinha-rust | entered the Rinha to find out how much you can still squeeze out of 1 CPU and 350 MB |
| gh-prs | wanted to know who actually reviews PRs on the team. became a CLI and ended up on npm |
| my-react-version | rewrote React to understand React |
| flowcontrol | I have a mac and a windows machine on the same desk and got tired of two keyboards |
away from the keyboard
Speedcubing and chess. Cycling when I can, Brazilian music all the time.
I write everything in Zed, on the base16 Oxocarbon Dark theme. The {my-theme} button up top repaints the site with its colors — the same ones I stare at all day. The default here is quieter on purpose.