- Page loads quickly - should be able to serve the initial page in < 100ms
- No weird flashes during loading (elements don’t “pop in” or rearrange during loading)
- No obvious defects when the page is resized to different screen sizes
- No obvious CPU lag during interactions
- Making a modification to some value on the page updates it everywhere it’s used (no page refresh required)
- Interactions don’t weirdly lag - if some operation is asynchronous and takes a few seconds, a spinner gets displayed