Reactivity & Data Management Interview Questions

Reactivity is Vue's system for automatically updating the DOM when data changes. Uses Proxy-based reactivity in Vue 3, Object.defineProperty in Vue 2. Tracks dependencies and triggers updates automatically.

Computed properties are cached reactive values that update when dependencies change. Define using computed() or computed option. More efficient than methods for derived values.

Watchers observe reactive data changes and execute callbacks. Use watch option or watch() function. Support deep watching and immediate execution. Handle side effects.

Use array methods that trigger reactivity (push, pop, splice). Avoid directly setting array indices. Use spread operator for immutable updates. Handle array reactivity limitations.

ref creates reactive reference to value. Access via .value in script. Automatically unwrapped in templates. Handles primitive values and objects. Example: const count = ref(0).

Use reactive() for objects, ref() for primitives. Handle nested reactivity. Support deep reactivity. Implement reactive patterns. Example: reactive({ count: 0 }).

shallowRef and shallowReactive create shallow reactive references. Only top-level properties are reactive. Useful for large objects. Better performance for specific cases.

Use triggerRef() for refs, trigger component updates with nextTick(). Force component re-render. Handle manual reactivity. Example: triggerRef(myRef).

Create readonly versions of reactive objects using readonly(). Prevent mutations. Support readonly refs. Implement immutable patterns. Example: readonly(state).

Use watchers instead of computed for side effects. Handle async computed. Support computed caching. Implement computed patterns.

Use deep reactivity with reactive(). Handle nested objects and arrays. Support deep watching. Implement nested patterns.

Cache computed results. Handle cache invalidation. Support cache strategies. Implement caching patterns. Handle cache management.

Use Vue devtools. Track reactive dependencies. Support debugging tools. Implement debugging strategies. Handle reactivity issues.

Create reusable reactive patterns. Handle state sharing. Support composition. Implement pattern libraries. Handle pattern management.

Use reactive Maps and Sets. Handle collection methods. Support collection reactivity. Implement collection patterns.

Create persistent reactive state. Handle storage sync. Support storage patterns. Implement storage strategies. Handle storage management.

Implement middleware for reactive updates. Handle transformation pipeline. Support middleware chain. Implement middleware patterns.

Create complex reactive architectures. Handle advanced patterns. Support system composition. Implement advanced strategies.

Optimize reactive updates. Handle large datasets. Support performance monitoring. Implement optimization strategies.

Create reactive test suites. Handle test scenarios. Support integration testing. Implement test strategies. Handle test coverage.

Implement security measures. Handle data protection. Support secure patterns. Implement security strategies.

Track reactive system metrics. Handle performance monitoring. Support debugging tools. Implement monitoring strategies.

Design scalable reactive systems. Handle system organization. Support architecture patterns. Implement design principles.

Create comprehensive documentation. Generate API docs. Support example usage. Implement documentation systems.

Implement deployment strategies. Handle environment configuration. Support production optimization. Implement deployment patterns.

Handle system upgrades. Support version migration. Implement migration strategies. Handle compatibility issues.