I spent four months building a React app. Polished UI, fast load times, clean code. Then I checked Google Search Console and nearly threw my laptop out the window. Zero indexed pages. Zero. Turns out I had been shipping a beautifully crafted ghost town, and every JavaScript developer I've talked to has hit this wall at least once. If you're building with React, Next.js, Vue, or any JS-heavy stack, the SEO checklist for JavaScript apps is different from what most tutorials teach. The WordPress-era advice will quietly mislead you. Let me share the exact checklist I now run through on every project before it ships. SEO Checklist Step 1: Solve the JavaScript Rendering Problem First The first item on any SEO checklist for JavaScript developers is rendering. Googlebot can execute JavaScript, but it does not always wait for it. By the time it crawls your page, your useEffect() has not fired, your API call has not returned, and your <title> tag is still an empty string.…