An engineer shipped 150,000 lines of vibe-coded Elixir, then wrote the honest post-mortem

Three categorical failure modes emerged. (1) Architecture: Claude defaults to creating new files everywhere. It repeats code it’s already written. It introduces inconsistencies. Architectural judgment remained fundamentally human work. (2) Idiom drift: Claude produced defensive nil-checking, early returns that don’t make sense in a functional context rather than Elixir’s assertive pattern-matching style. The fix required being strict about what good Elixir looks like. (3) Concurrency: Claude doesn’t understand how processes, the actor model, and GenServers work together. When debugging async code, it feeds itself bad data. It gets very lost. Database testing exposed similar blindness — Claude tried to seed test databases without understanding that each test runs in a database transaction that rolls back at the end. All three required constant human intervention to recover.

A solo founder crossed $200K on a dictation app — almost all lifetime deals, almost no MRR underneath

Total revenue crossed $200K. But almost all of it came through lifetime deals. The recurring number underneath was way smaller — far below what a $200K headline implies in MRR terms. Profit margin held around 92% (excluding Apple’s tax) because the device-reuse + solo-ops model kept costs near zero.

An indie founder registered a business before writing any code, then built a LinkedIn outreach SaaS with Claude — first month ~$2K

First month after launch: roughly $2K in revenue. The build had taken most of the year, with the legal entity acting as the slow-burn deadline. They shipped a working browser-based automation tool into a niche dense with established competitors (PhantomBuster, Apollo.io, Seamless.ai) right as those competitors were starting to get banned by LinkedIn for fingerprintable headless automation.

Causo.ai hit Product Hunt #5 — the founder followed up 72 hours later with the actual numbers

Launch day: 110+ visitors, 68 signups. Signup conversion at 60%+ of visitors — unusually high for PH. Paying conversion still undetermined 72 hours later, not enough data to draw the line yet. Newsletter mention status hadn’t resolved.

A nights-and-weekends solo dev published 800 programmatic SEO pages — Google indexed 120 in the first month

30 days in, Google had indexed 120 of the 800 pages — 15%. Far below the conservative expectation. I ran into an SEO problem recently that I didn’t expect to be this annoying. Search traffic essentially zero, with no signal of which subset of the 120 indexed pages might rank for anything.