Vue.js Developer interview questions

Best practices include encapsulating functionality into small, reusable components, following atomic design principles, using slots and scoped slots for flexibility, managing props and events for clean communication, and enforcing consistent file structures such as atomic, feature-based, or domain-driven organization.

Efficient state management involves structuring state into modules, leveraging namespacing, keeping mutations synchronous, using actions for asynchronous logic, applying strict mode in development, normalizing state shape, and avoiding excessive global state by encapsulating data when possible.

Strategies include using computed properties and watchers wisely, minimizing deeply nested data reactivity, leveraging the v-once and v-memo directives, breaking down large components, controlling update frequency with debounce/throttle, and utilizing async components to split code.

Complex communication can be managed using Vuex for state sharing, providing and injecting dependencies, employing event buses judiciously, using scoped slots, and passing data through props while emitting custom events upwards in the component hierarchy.

Understanding the Vue.js lifecycle allows proper allocation and cleanup of resources such as network requests or subscriptions in created/mounted and beforeUnmount/unmounted hooks, ensuring side effects are managed and application performance is optimized.

Advanced patterns include dynamic components with the component tag, lazy loading via async components, rendering functional components for stateless use-cases, leveraging render functions for custom render logic, and using key props to control element reuse efficiently.

Techniques include utilizing Vue Devtools to inspect state and mutations, integrating plugins for logging or time-travel debugging, applying strict mode to catch improper mutations, and instrumenting code with watchers or middleware for detailed analysis.

Optimizing for maintainability involves enforcing consistent coding standards, modularizing and reusing components, documenting component APIs, employing TypeScript or prop validation, automating testing routines, and regularly reviewing architecture as applications grow.

Common pitfalls include not declaring all reactive properties upfront, mutating arrays/objects in non-reactive ways, reliance on deep watchers unnecessarily, or improper use of refs in Vue 3. Avoidance requires following documented guidelines for reactivity and using utilities like reactive and ref properly.

Side-effect management is achieved by isolating API calls and subscriptions into dedicated lifecycle hooks like mounted or beforeUnmount, handling asynchronous side effects within Vuex actions, ensuring clean-up logic is addressed, and consistently scoping effects to the component or module lifecycle.