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Open Source Contributor C · Rust · PowerPC ASM · Dolphin

Open source contributor to Project Slippi, the netplay and stats platform for competitive Super Smash Bros. Melee.

Highlights

  • Built a live in-game rank display for Slippi's ranked matchmaking.
  • Wrote a Rust backend that fetches rank data from the Slippi API and streams it into Dolphin.
  • Reworked the Sheik / Zelda character selector, rewriting the original PowerPC assembly logic in C.
The rank display is a live in-game view of the player's Slippi rank, shown on the character select screen during ranked matchmaking. The widget displays the player's rank icon and rating, and plays an animated ticker when their rating changes after a match. Players who haven't finished their placement matches see a placeholder showing how many matches they have left.
The frontend is written in C and rendered with the game's own UI systems, with the rank icons packed into the character select screen's menu files as a texture animation. The backend is written in Rust as part of Slippi's Dolphin integration. It fetches rank data from the Slippi API on a background thread, retrying while the server processes the match result, and streams the data into the game. I first prototyped the feature in 2023 against the old C++ Dolphin fork, then rewrote the backend during Slippi's Rust migration before it was merged in 2025.

here's a preview of some of the slippi rank info stuff ive been working on recently. source code on github for anyone who would like to try it out / contribute: https://t.co/adSUwTPt66 pic.twitter.com/V8YU0HYSZ8

— walz (@walz_dev) September 18, 2023
A rework of the Sheik / Zelda selector on the character select screen. The original selector was just text that read "(S) / Z", with the parentheses denoting which character was selected. I replaced it with a toggle switch that uses the two characters' stock icons. The selection logic was originally written in PowerPC assembly, which I rewrote in C along with new hover and selection behavior. The rework was merged into Slippi in 2025.
The switch UI is built directly into the game's character select screen files. I authored the new textures and joint structure in HSDRaw and added them to the menu's dat file, the same way the game stores its native UI.