I've shipped stuff used in parts of Latin America and Southeast Asia and one of the biggest lessons was this: latency, not bandwidth, is what kills UX. A 10mb

I've shipped stuff used in parts of Latin America and Southeast Asia and one of the biggest lessons was this: latency, not bandwidth, is what kills UX. A 10mb download over 3G is fine if you can actually start it. But when the page needs 15 round trips before first render, you're already losing the user. We started simulating 1500ms+ RTT and packet loss by default on staging. That changed everything. Suddenly we saw how spinners made things worse, how caching saved entire flows, and how doing SSR with stale-while-revalidate wasn’t just optimization anymore. It was the only way things worked. If your app can work on a moving train in Bangladesh, then it's gonna feel instant in SF.