Your ruby.wasm Doesn't Quite Work on Mobile
- Time
- 2026-08-09 10:10 ~ 10:40
- Speaker
- Mu-Fan Teng
- Room
- TR514
- Co-write
- https://hackmd.io/SkldlNx8Gl
Abstract
At SITCON 2026, the Ruby Taiwan booth ran a live coding game: a Jekyll static site + ruby.wasm 4.0, with students writing one-line Ruby in the browser. Simple in concept, brutal in practice.
Day one, we found out: iOS Safari froze, Android Chrome silently hung at load, students who switched apps lost their progress. The booth that served 1000 students was held together by fixes for three mobile-browser landmines.
This talk takes you into the engine room: how we replaced a giant EXPECTED_MAP with rubyVM.eval + StringIO + srand(seed) to compute answers in the browser; how zh/en/ja i18n flows from Liquid into JavaScript; how the 7 Ruby + 3 cross-language (JS/Python/PHP) format works; and the real root cause behind each mobile bug.
For anyone curious about ruby.wasm, Ruby in the browser, or pushing Ruby beyond Rails.
Speaker
Mu-Fan Teng
鄧慕凡 (Mu-Fan Teng / Owaru Ryudo)，Ruby Taiwan 總召，寫 Ruby 第 19 年。白天寫 Rails，晚上和週末把 Ruby 推到 web app 以外的地方 — 攤位遊戲、教學工具、IoT 玩具、ruby.wasm 實驗。常在 COSCUP、SITCON、RubyConf TW 的 Ruby 攤位後面負責解釋「為什麼你應該寫 Ruby」。相信讓人寫到第一行 Ruby，比讓人讀第一篇 Ruby 文章重要。
Mu-Fan Teng (Owaru Ryudo) is the Chief Organizer of Ruby Taiwan and a 19-year Rubyist. Rails by day; by night and weekend, he pushes Ruby into places it doesn't belong yet — booth games, teaching tools, IoT toys, ruby.wasm experiments. You'll find him behind the Ruby booth at COSCUP, SITCON, and RubyConf TW, explaining why you should write Ruby. He believes getting someone to write their first line of Ruby matters more than getting them to read their first Ruby article.