Snack bars, also known as toasts, are popular. But they’re almost always absolutely positioned, obscuring content in unexpected and annoying ways.
Take LinkedIn. It’s snackbar does not have a timeout. Moreover, they stack and unlimited number of times. This Makes for a very annoying job application process on the site.
We can do better, and some already do.
GitHub’s notifications view is an excellent example. They make it easy to know when there’s something new, and easy to manage old notifications.
So use snack bars sparingly, if you must use them at all. They can easily overwhelm your users and cause unintended frustration.