Frontend System Design
/Advanced
Incremental Static Regeneration
Definition
ISR allows you to create or update static pages after you've built your site. You define a revalidation time (e.g., 60 seconds). When a request comes in after 60s, the CDN serves the stale page but triggers a background rebuild of that specific page.
Explain Like I'm New
It's SSG, but with an expiration timer. Once the timer expires, the next user gets the old page, but it secretly tells the server to bake a fresh page for everyone who comes after them.
Interview Questions
basic
- What is the core concept of ISR?
- What are the pros and cons of ISR?
intermediate
- How does ISR impact SEO and initial page load times?
- When would you NOT choose to use ISR?
advanced
- How does ISR fit into a heavily scaled microservices architecture?
- What are the security implications of ISR?
trick
- Can you combine ISR with other rendering strategies on the same page?