WeChat Mini Program Performance Optimization

My approach follows a measure-first methodology. First, I use the WeChat Developer Tools Audits panel and real-device performance traces to baseline metrics: startup time (target under 1.5s), first meaningful paint, and scroll FPS (target 60fps). For startup optimization, I'd implement subpackage loading — move non-critical pages into subpackages to reduce the main package from, say, 2MB to under 1MB. I'd also preload API data during app.onLaunch in parallel with page initialization, and display a skeleton screen immediately. For scroll performance, the most common issue is excessive setData calls. I'd audit all setData invocations: batch multiple updates into single calls, reduce payload by sending only changed fields using diff algorithms, and replace scroll-bindable animations with WXS IntersectionObserver to avoid cross-thread communication. For long lists, I'd implement a virtual scroll component that renders only visible items plus a small buffer. Memory optimization includes using wx.createIntersectionObserver to lazy-load images and setting src to empty string for off-screen images to trigger garbage collection.