Netflix Frontend Engineer System Design Questions

To enhance user engagement and content discoverability, Netflix aims to implement a user-specific watchlist system allowing users to save their preferred content for future viewing.
Design a class WatchList that allows users to manage their watchlist with the following features:
- add(contentId: string): Adds a content ID to the watchlist.
- remove(contentId: string): Removes a content ID from the watchlist.
- getAll() -> List[string]: Returns a list of all content IDs in the watchlist.
- contains(contentId: string) -> bool: Checks if a content ID is present in the watchlist.Example 1:
Input: watchlist = new WatchList(); watchlist.add('content123'); watchlist.getAll()
Output: ['content123']
Explanation: The content ID 'content123' is successfully added to the watchlist.Constraints:
- The contentId strings are unique and valid.

As Netflix's platform scales, creating a seamless user experience necessitates designing an efficient client-side routing system to manage navigation and view states across the application.
Implement a class Router to manage routes and navigation within the application, with the following functionality:
- addRoute(path: string, component: Function) -> void: Adds a new route with an associated component.
- navigate(path: string) -> void: Navigates to the specified route, rendering the associated component.
- getCurrentRoute() -> string: Returns the current route.Example 1:
Input: router = new Router(); router.addRoute('/home', Home); router.addRoute('/about', About); router.navigate('/home'); router.getCurrentRoute()
Output: '/home'
Explanation: Navigating to '/home' renders the Home component and updates the current route to '/home'.Constraints:
- All path strings are unique.
- Each component is a valid Function reference.
- Concurrent navigation requests may occur, which should be handled gracefully.