How to Optimize React & Next.js Apps for SEO and Rank Faster

I spent 3 hours debugging why Google couldn't see my React app. Turns out, Googlebot was rendering a blank white page — because my entire content lived inside client-side JavaScript that hadn't loaded yet. The fix was 4 lines of code. But getting to those 4 lines cost me a week of confused Google Search Console reports, zero indexed pages, and a growing suspicion that SEO for single-page applications is fundamentally broken. It's not broken. It's just different — and most tutorials skip the hard