SSR / SSG / Hybrid Rendering (Deep Workflow)

Rendering is an architecture decision, not a framework toggle. Guide users to map freshness, personalization, cost, and complexity per route—avoid “SSR everything” or “static everything” by default.

When to Offer This Workflow

Trigger conditions:

• Choosing rendering strategy for marketing vs app shell vs dashboards
• SEO + auth + dynamic data conflicts
• Slow TTFB, stale content, or expensive server work per request
• Hydration bugs, double data fetch, or client/server environment mismatch

Initial offer:

Use six stages: (1) route & data classification, (2) choose rendering mode(s), (3) data loading & cache layers, (4) streaming & partial SSR, (5) hydration & client boundaries, (6) validate (SEO, perf, ops). Confirm framework and hosting (Node server, serverless, edge).

Stage 1: Route & Data Classification

Goal: Each route has clear freshness, auth, and personalization needs.

Dimensions

• Public vs authenticated: can HTML be shared or per-user?
• Update frequency: static marketing, hourly blog, real-time inventory
• Source of truth: CMS, DB, API with rate limits, edge KV

Output

A matrix: route pattern → public/private → max staleness acceptable → personalization level.

Exit condition: No ambiguous “dynamic page” without stating what changes and how often.

Stage 2: Choose Rendering Mode(s)

Goal: Pick SSG, SSR, ISR/ondemand revalidate, CSR with SSR shell, or edge—per route.

Heuristics

• SSG / prerender: stable content, best TTFB/CDN cache, great SEO—watch rebuild/revalidate story
• SSR: must reflect request-time data (A/B, geo, auth gating) or strict freshness
• Client-heavy: acceptable for post-auth app surfaces if SEO not needed
• Hybrid: static shell + client islands; or static generation with server components for parts (framework-specific)

Trade-offs

• SSR cost and latency vs SSG staleness
• Edge rendering: geography and limits (CPU, Node APIs)

Exit condition: Documented per-route strategy with rationale.

Stage 3: Data Loading & Cache Layers

Goal: One coherent story for where data is fetched and how it is cached (CDN, full-page, data cache, edge).

Practices

• Cache-Control / surrogate keys / tag-based invalidation—align with framework primitives (e.g., revalidate, fetch cache)
• Deduplicate requests between server and client where frameworks allow
• Avoid accidental private data in shared cache—vary by cookie/auth correctly or disable cache

Stale-While-Revalidate

• Great for mostly fresh—document user-visible staleness acceptance

Exit condition: Data flow diagram: origin → edge → browser; invalidation owner identified.

Stage 4: Streaming & Partial SSR

Goal: Improve perceived performance with suspense/streaming where supported.

Guidance

• Defer slow fragments; show skeletons with accessible semantics
• Ordering: ensure critical LCP resources not blocked by deferred junk
• Headers: understand chunked response implications for intermediaries

Exit condition: Slow dependencies isolated; UX fallbacks defined.

Stage 5: Hydration & Client Boundaries

Goal: Correct interactive UI without double work or mismatches.

Checklist

• Server/client component or module boundaries (framework-specific)
• useEffect vs server fetch duplication—waterfalls
• Environment: no window on server; no secret APIs in client bundles
• Hydration mismatch: locale, random IDs, time—suppress or serialize state

Exit condition: Known interactive islands listed; mismatch risks mitigated.

Stage 6: Validate (SEO, Performance, Ops)

Goal: Rendering choices show up correctly in search, metrics, and logs.

SEO

• View source / rendered HTML for critical content; meta and canonical per mode
• Auth: soft paywalls—decide what crawlers see ethically and technically

Performance

• TTFB vs FCP/LCP; server time vs edge cache hit
• RUM segmented by route and cache hit

Ops

• Cold starts on serverless SSR; concurrency limits; regional failover

Final Review Checklist

• [ ] Per-route rendering choice documented with freshness/personalization
• [ ] Caching and invalidation story is explicit and safe for auth
• [ ] Streaming/skeletons don’t harm LCP or a11y
• [ ] Hydration and env boundaries verified
• [ ] SEO and RUM validation for top templates

Tips for Effective Guidance

• Name staleness in seconds/minutes—“real-time” is rarely real-time.
• When user uses Next.js, tie advice to App Router vs Pages semantics explicitly if known.
• Warn: edge ≠ full Node—API surface differs.

Handling Deviations

• SPA-only: focus on meta for landing routes and prerender for marketing if added later.
• No server: SSG + client or external prerender service—be honest about limits.