SaaS Launch Checklist: Everything You Need Before Day 1

You've built the product. The code works. The landing page looks good. But launching a SaaS isn't just flipping a switch — it's coordinating dozens of moving pieces across engineering, marketing, legal, and operations. I've seen launches fail not because the product was bad, but because the founder forgot to set up transactional emails, didn't have a billing recovery flow, or launched without analytics and had no idea where signups were coming from. This checklist covers everything you need before Day 1. Bookmark it, fork it, check things off as you go. 🏗️ Product & Engineering Core Product [ ] Core user flow works end-to-end. Sign up → onboard → use key feature → get value. Test it with 5 people who aren't you. [ ] Authentication is solid. Email/password, OAuth, magic links — pick at least two. Use a proven auth provider (Clerk, Auth0, Supabase Auth). [ ] Error handling is user-friendly. No stack traces in production. Every error should tell the user what happened and what to do next.