Bambú Studio: Core Web Vitals sprint — 63→97 in days

WordPress (LiteSpeed + QUIC.Cloud) — 5 days — LCP 6.3s→1.7s · CLS ≈0→0.001

Bambú Studio (before) • Performance 63 • FCP 3.3s • LCP 6.3s — PSI mobile, 4G, 8/03/2025

Context (The real problem)

The homepage looked great, but on mobile the first render was slow and the largest element (hero) arrived too late. Third-party scripts competed for early bandwidth and some assets lacked intrinsic dimensions. Result: hesitation before scrolling and a sluggish first impression.

From diagnosis to real gains (the sprint)

We ran a mini audit from PSI (mobile, 4G) to map the highest-impact items: slow LCP (6.3s), late hero image, render-blocking CSS/JS, and third-party scripts loading too early. We attacked quick wins first and validated every change.

What we did — Performance

• Responsive images (srcset/sizes) + AVIF/WEBP and fetchpriority="high" on the hero to shorten the critical path.
• Explicit width/height (or aspect-ratio) for above-the-fold media to avoid reflow.
• Reordered enqueues (CSS/JS) and added safe minify/combine exclusions to remove render-blocking.
• Gated/deferred third-party scripts (analytics/widgets) beyond the LCP window.
• Font policy with display=swap and preconnect where needed to avoid FOIT.
• LSCache + QUIC.Cloud tuning (cache TTLs, HTML/JS minify with safe excludes) without breaking UX.

What we did — UX & Stability

• Stabilized header behavior and reserved space for above-the-fold elements (predictable layout on small viewports).
• Reduced non-critical animations on first view to keep the main thread quiet.

What we did	Why
Hero preload + priority (fetchpriority) with srcset/sizes (AVIF/WEBP)	Brings first-visible content sooner → lower LCP and instant sense of speed.
Explicit dimensions for above-the-fold images	Prevents layout shifts → pages feel solid and trustworthy (CLS ~0.001).
Reorder enqueues + exclude risky minification	No render-blocking and no UI breakage; safely improves FCP and Speed Index.
Third-party gating/defer (analytics/chat/widgets)	Frees the main thread as users start interacting; reduces LCP noise.
Font policy (display=swap + preconnect)	Text shows fast without flicker; immediate readability.
LSCache + QUIC.Cloud tuning	Lower latency and lighter HTML without sacrificing cart/checkout.
Lazy-loading for off-viewport media	Saves data on 4G and keeps scrolling smooth.
Staging QA + repeated measurements	Stable improvements, not lab-only spikes; low risk in production.

Bambú Studio (after) • Performance 97 • FCP 0.9s • LCP 1.7s • TBT 30ms • CLS 0.001 — PSI mobile, 4G, 13/03/2025

FAQ — Transparency first

• Do we always hit 100? No. Third-party scripts (ads, chat, maps, testing) can set a ceiling. We maximize what’s controllable and document limits/trade-offs.
• Will the design break? No. Iterative changes with tests; staging first when applicable.
• How long does it take? Quick audit in 48h; a typical sprint is 3–5 days depending on findings.
• What do you need from me? WP/hosting access, list of critical plugins and, ideally, a staging environment.