Designer’s role does not end at UX conceptualization, it actually should be on peak from there. Performance is one of the most essential parts of design. It plays a vital role in making products addictive. It also ensures a good user experience.

Along with formative and summative usability testing, there should be dedicated performance testing of each interaction. It’s important to evaluate how fast it responds and provides feedback. People don’t like to wait when trying to complete a task.

Offer system feedback within 400 ms to keep user’s attention and to increase productivity. As per Doherty threshold computer should take to respond before the user get bored.

If there isn’t much that can be done to improve the performance

There should be perception creation that a website is performing faster. One example is from the leading social media app Facebook. It shows a presentation of a skeleton screen when the content is loading. These blocks are progressively replaced with actual images. This replacement increases the perception of speed, even if content is loading slowly.

If the device responds faster, then user’s expectation

Change blindness may occur. A change that happens too fast be completely missed. It can be difficult for users to comprehend what happened because they do not have enough time for mental processing.