Astro Islands Architecture: When to Use Partial Hydration
I've shipped enough full SPAs to know their dirty secret: they're overly expensive for most websites. A marketing site doesn't need React hydrating a footer. A documentation portal doesn't need Vue managing a navigation bar. Astro's Islands architecture fixed this for me, and I'm not going back.
The Islands pattern is simple: ship static HTML by default, hydrate only the interactive pieces. You get the performance of a static site with the interactivity of a modern app. In practice, this means your Lighthouse scores stop being a source of shame.
The Problem with Full Hydration
Before Islands, I had two choices:
