Abstract task: a feature was rolled out, and a week later users complain that the page freezes. How would you go about finding the problem?

To identify the cause of a page freeze after releasing a new feature, you can sequentially perform the following steps:

1. Gather information from users: clarify on which devices and browsers the issue occurs, and what actions lead to the freeze.

2. Check logs and monitoring: review server and client logs, performance metrics, JavaScript errors.

3. Use browser developer tools:

   • Profile performance (Performance tab) to identify long operations.
   • Check memory usage (Memory tab) for leaks.
   • Track network requests (Network tab) for delays or errors.

4. Isolate the problem: disable the new feature or parts of the code to see if the issue is specifically related to it.

5. Check loops and event handlers: there might be infinite loops or too frequent UI updates.

6. Conduct code review: examine changes for potential blocking operations or heavy computations.

7. Test on different devices: to understand if the issue depends on device performance.

This systematic approach will help localize and eliminate the cause of the freeze.