About
I'm Celso. I live in Curitiba, Brazil, I work as a product engineer at Salvy and I've been studying Computer Science at UP since 2024 — which means studying compilers the same month I'm arguing about an invoice with the support 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. Both work.
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.
| 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.