April 30, 2026
WASM bam, thank you ma’am
I Built a WebAssembly Runtime in 5 Days
He ditched pricey cloud bills, but commenters came for the brag and the AI vibes
TLDR: A founder says he replaced expensive cloud tools with a homemade system built in five days on a cheap server. Commenters were split between impressed, skeptical, and openly mocking, arguing over whether he truly built something new or mostly stitched together existing tools with AI help.
A startup founder says he built his own mini version of a cloud service in just five days because he was sick of paying big-company prices for tiny workloads. The basic idea is simple enough for non-experts: instead of renting expensive tools from giants like Amazon or Microsoft, he hacked together his own locked-down system on a cheap private server so customer code could run safely online. It's a classic scrappy-underdog story — and the community immediately turned it into a popcorn-worthy comment fight.
The biggest reaction? A brutal identity crisis over what was actually built. One commenter flat-out asked why the post keeps saying he built a WebAssembly runtime when he was really using an existing one, Wasmtime. Ouch. Another reader gave the post a polite golf clap, saying the write-up was useful, but also had a devastatingly funny read on it: it felt like “days of vibe-coding,” the kind of project where an AI assistant does the typing while the human supervises. And then came the full eye-roll brigade, with one commenter basically translating the article as: “I got a chatbot to summarize the work it did while I checked Cursor.”
Not everyone was there just to sneer. A more security-minded reply warned that if you're letting different customers use the system, you should treat each run as disposable because leftover state can stick around in weird ways. So while the article sells a fast-moving hacker triumph, the comments turned it into a three-way brawl over credit, safety, and whether this is genius bootstrap energy or just another AI-assisted victory lap.
Key Points
- •The article describes a hardware startup co-founder building a self-hosted WebAssembly sandbox platform called Badwater to avoid the cost of cloud signing and infrastructure services.
- •The system was intended to support tasks such as firmware signing, device activation, and OTA delivery while safely running untrusted code.
- •The author chose WebAssembly and WASI Preview 2 because they provided sandboxing, small binaries, and in-sandbox networking support for HTTPS requests.
- •During implementation with Wasmtime, the author found that WebAssembly components required `wasmtime::component::Linker` rather than the APIs commonly shown in core module tutorials.
- •A Tokio runtime conflict caused a host panic when the guest made HTTPS calls, and the article says the issue was resolved by moving Wasmtime execution into `spawn_blocking`.