I run a side project: a gas price finder that's mostly programmatic content. Roughly 33,620 ZIP code pages plus a few hundred state and city pages, all built on Next.js 15 with ISR. It runs on Vercel, fronted by Cloudflare for DNS. For about eight months it was indexing fine. Traffic was small but growing. Then on April 11 I checked Google Search Console and saw something I'd never seen at this scale: 87 URLs flagged as "not found (404)," 61 flagged as "soft 404," and a chunk of others sitting in "crawled, currently not indexed." I'm a data analyst. This is my side project, not my day job. So I had a weekend, a coffee subscription, and the GSC export. Here's the four-phase recovery, what each phase actually fixed, and the things I'd do differently. What the damage actually was GSC's URL Inspection tool is the only way to figure out what Google thinks of any specific URL. The 87 hard 404s broke down into two groups when I sampled them: Stale city slugs.…