When an interviewer asks this, they’re testing two things:

1. Do you understand rendering modes deeply (performance, infra cost, DX)?
2. Can you make a decision based on product requirements, not hype?

🌐 Client-Side Rendering (CSR)

When to choose it:

• The page is highly personalized (e.g., user dashboards, recommendation feeds)
• SEO doesn’t matter
• Heavy client-side interactivity
• Data changes constantly (e.g., metrics dashboards)

Pros: Fast subsequent navigation, Simple deployment, Works insanely well with caching libraries

Cons: Slow first load (JS bundle + API calls), Poor SEO, Users on slow networks feel the pain

Where I'd use it:

• Logged-in app routes
• Control panels, admin panels, analytics dashboards

🧱 Server-Side Rendering (SSR)

When to choose it:

• You need good SEO and TTFB