Name several reasons why a website is not performing well or is slow to respond to user prompts.

During an interview, the hiring manager seeks to fully understand your competencies and abilities related to the position for which they are interviewing you. This particular question seeks to determine your ability to diagnose and address the poor performance of a website. Since the question is rather general, the best way to respond is by citing 2 to 3 examples of why a website is performing badly and what you would do to fix them.

"Poor performance of a web site may be due to several reasons, all of which can be addressed once they are diagnosed. For instance, one reason may be render-blocking by JavaScript, which is delaying page loads. This is caused by a browser waiting to fully load any JavaScript files before they display them. The problem can be solved by using asynchronous loading, removing external JavaScript files, or deferring the JavaScript loading until the rest of the page has become visible. Other issues that may impact the performance or speed include excessive overhead in your database, the site's CSS not being optimized, and OPcache not being enabled. Once any of these causes have been identified as the problem, solutions can be implemented similar to the example I've already provided."