Rust is the answer to the wrong question

An engineer describes evolving a Rails CRUD app for dance competition scheduling into a system that must also run offline in judges' browsers and phones. That offline requirement pushed the author to transpile ERB views and minimal business logic into client-side code, which forced serious type inference - tracing instance variables back to controllers and models to distinguish arrays from hashes. That work led to Roundhouse and Spinel: a transpilation toolchain that can emit CRuby, Spinel, Rust, and even Kotlin/Swift, letting a three‑tier Rails app run in the browser with sourcemaps, breakpoints, and watch-mode tests. Demos and downloads show Rails features preserved (TailwindCSS, TurboStreams, Action Cable), and deployments can target Vercel+Neon or Cloudflare Durable Objects without rewriting. Making outputs monomorphic improved performance; emitting Rust as a target sped both Spinel and CRuby.

The core argument is that switching languages - Rust included - is a red herring when the real problem is long‑term maintenance and unexpected requirements. One‑shot rewrites optimize initial authoring but fail to solve security and evolving needs. The practical solution offered is a rock‑solid contract layer or DSL with explicit escape hatches and a compiler that captures intent rather than mechanism, enabling safe, optimizable multi‑target outputs without repeated full rewrites.