Vue Guideline: Performance — Use v-memo for expensive lists. Description: Memoize list items. Do: v-memo with dependency array. Don't: Re-render entire list always. Good Example: <div v-for v-memo="[item.id]">. Bad Example: <div v-for> without memo. Severity: Medium. Docs: https://vuejs.org/api/built-in-directives.html#v-memo.