My pages ship a lot of JavaScript that runs on load to make everything interactive, and on slower devices the page looks ready but doesn't respond to taps for seconds (main thread busy). Reduce the client-side work my pages do on load: 1. Measure the problem: total blocking time and main-thread work on my key pages using a throttled CPU profile. Identify which components/libraries account for the most scripting time on load. 2. Find over-interactive components: things that ship JS behavior but are static 99% of the time (marketing copy sections, footers, static cards, content that never changes after render). Make them plain HTML with no client-side JS. 3. Defer interactivity below the fold: components the user can't see yet shouldn't execute their setup code on initial load. Lazy-hydrate or initialize on visibility/interaction. 4. Check for duplicate rendering: components that render on the server and then immediately re-render on the client with the same data, doubling the work. Fix state initialization so the client picks up where the server left off. 5. Audit load-time initialization: analytics, observers, event listeners, timers set up for components before they're needed. Defer what's deferrable. Don't remove interactivity users expect (menus, forms, live data) to hit a metric; the goal is less work for the same behavior. The deliverable is the measurement first, then the specific changes ranked by main-thread time saved, with before/after total blocking time on a throttled profile.