Question 1

What is Angular SSR and why use it?

Accepted Answer

Render pages on the server for faster first paint and better SEO/social previews. Angular Universal / @angular/ssr generate HTML before hydration. Mind browser-only APIs during server render.

Question 2

How do you avoid breaking SSR with window/document usage?

Accepted Answer

Guard with isPlatformBrowser, inject DOCUMENT carefully, or move code to afterNextRender. Using window at import/constructor time crashes SSR. Prefer abstracting browser APIs behind services.

Question 3

What is TransferState used for?

Accepted Answer

Passing server-fetched data to the client to avoid duplicate HTTP calls after hydration. Store responses during SSR; read on client. Prevents flicker and double fetch. Keys must be stable.

Question 4

When is SSR the wrong tool?

Accepted Answer

Highly interactive authenticated apps with little public SEO value may not justify SSR complexity. Consider SSG for mostly static marketing pages. Measure TTFB and caching strategy.

SSR Angular Interview Questions

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