I Built a Scheme Compiler with AI in 4 Days

A developer whipped up “Puppy Scheme,” a tiny programming language compiler that turns code into WebAssembly (think: fast, portable tech that runs in browsers and servers) — in just four days with AI. Overnight, he told Claude to “grind on performance,” and compilation dropped from 3½ minutes to 11 seconds. Cue the comment fireworks. Skeptics instantly pulled out the classics like “Write Yourself a Scheme in 48 Hours”, asking if this is really new or just a shiny remix. Others went full hype, saying AI isn’t just copying — it’s creating.

The hottest thread is the “is AI an unpaid intern or a co-author?” debate. One dev bragged their own Scheme compiler was “100% written by Claude” with heavy testing, while another warned they keep hitting bugs but Claude patches each one — like a tireless night-shift coder. A mini identity drama popped up when someone wondered if the “near production” claim ties to Astro’s build-with-AI guide. Meanwhile, the crowd loves the name: “Puppy Scheme” sparked dog puns (“Claude fetched the speed!”), and meme-y disbelief that a language compiler is now a weekend project. Tech acronyms flew — R5RS/R7RS are just Scheme’s rulebooks, WASI is how WebAssembly talks to the system, GC means auto-cleanup — but the real vibe is clear: we’ve entered the DIY software time warp, and it’s messy, fast, and hilarious.