Override default validation messages and show them as modals instead of inline, entirely through config.
Validate a radio group and standalone checkboxes independently, and handle their array-of-errors return shape.
Score a password as the user types and show a strength bar, label, and suggestions.
Split a signup form across steps and validate each step before advancing, using a declarative field config.
Validate a login form on the client, then submit it via AJAX without a page reload.