What are the key differences between Vue 2 and Vue 3?
Assesses fundamental understanding of Vue.js conventions, runtime behavior, and memory/performance considerations.
Hiring managers look for precision, avoidance of ambiguous jargon, and ability to explain trade-offs under real production conditions.
| Feature | Vue 2 | Vue 3 |
| ------------------ | ------------------------- | ------------------------------------ |
| API Style | Options API | Composition API + Options API |
| Reactivity System | Object.defineProperty() | Proxy-based (faster & more reliable) |
| Performance | Moderate | Improved (~2x faster in some cases) |
| Tree-shaking | Limited | Fully tree-shakable |
| TypeScript Support | Partial | Built-in and first-class support |
| Fragment Support | Not supported | Supported |
| Teleport/Portals | Plugin-based | Native support |
| Suspense | Not available | Native support for async components |
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Candidate Response Strategy & Interview Tips
- Start with a concise one-sentence summary: Deliver a direct, confident answer first before expanding into nuances.
- Demonstrate real-world trade-offs: Discuss where this approach excels and when you would avoid it in production systems.
- Discuss complexity & edge cases: Proactively explain time/space complexity or boundary conditions (null values, scale limits).
- Prepare for interviewer follow-ups: Technical hiring panels frequently probe deeper into concurrency, backward compatibility, or alternative libraries.