Most indie builders ship apps without any real security in place, then wake up to $200 Supabase bills, spam attacks, or surprise cease-and-desist letters. At Ignyt Labs, they’ve launched over 60 MVPs in 1.5 years and learned the hard way that security isn’t a “version 2” feature—it’s the floor. They turned a Reddit post’s five-point checklist into a full 30-minute playbook that every founder should run before launch. The first step is legal: spend ten minutes grabbing a free privacy policy from Termly or PrivacyPolicies.com, map out where your data lives (Supabase region, Vercel region, third-party services), and make sure you’re not secretly selling or mishandling user info. Next, lock down your database with Supabase’s Row Level Security—no policies means anyone with DevTools can dump your entire tables. Then add server-side validation on every endpoint (Zod client checks aren’t enough) and replace detailed SQL or stack-trace errors with generic messages like “User not found.” Authentication and AI finish the checklist. Run four quick failure-case tests: five wrong-password attempts, reset on non-existent email, double-click on verify links, and reuse of an existing email. Those four tests catch about 80 percent of auth holes. Finally, feed your code into Claude Code or Cursor with four prompts—baseline security headers, OWASP alignment, data-leak audit, and API-key exposure check. In roughly eight minutes you’ll spot exposed .env values, over-verbose API responses, and keys in frontend bundles that can drain entire projects in a weekend.