From a user's perspective, one of the most frustrating things to encounter is when you interact with an interface and then...nothing happens.

You click a button, submit a form, toggle a switch, whatever, and then there's nothing but radio silence. What's missing? Feedback. A loading state on a button, a toast or popup message, a page refresh, something.

When it comes to designing UIs, as a front-end developer (really, any developer), it's absolutely essential that you remember to give the user feedback.

A quick example to make this concrete:

In the example above, we have two pieces of feedback: first, when we submit the form we disable the input and button and second, once the submission is complete we confirm it with a dialog.

For the first bit, we're giving feedback that the user's click did trigger a submission and with the second, we're giving feedback that the submission was successful. Both add a level of comfort to the process and make it clear that the intended action occurred as expected.

"ABGF, ABGF, ABGF"

When building your UI, make a point to always be mumbling "ABGF" to remind yourself to add feedback after interactions. When it comes to increasing adoption of your app and reducing support requests, feedback can be an easy, quick weapon to deploy to keep users happy and engaged.