Problem Statement
What are the common sources of rendering bottlenecks in Vue, and how do you diagnose them?
Explanation
Bottlenecks usually come from large lists without keys, deep reactive objects triggering wide updates, heavy computed/watch logic, and unnecessary re-renders via v-if/v-for misuse. Diagnose with Vue Devtools (Component tree, perf timeline), browser Performance tab, and flame charts to see slow updates and costly layouts.