Incremental Static Regeneration (ISR): A flexible way to cache dynamic content

What this post added

This post introduces Incremental Static Regeneration (ISR) as a caching strategy that combines static site generation (SSG) and server-side rendering (SSR) to deliver dynamic content at cached speeds. It details the benefits of ISR, including cached speeds with live content, selective regeneration, on-demand invalidation, and guaranteed cache durability. The post explains how ISR fits into Vercel's caching stack, alongside static assets, application-level caching, and client-side caching. It highlights framework adoption for ISR (Next.js, SvelteKit, Nuxt, Astro, Gatsby, Remix) and provides real-world scenarios in e-commerce, news websites, and AI-powered applications. The post also details implementation methods for ISR, including time-based regeneration with a SvelteKit example and on-demand regeneration with an Astro example using a bypass token and `x-prerender-revalidate` header.