1. Can we avoid a filter icon and show filters as they are?
2. If not, what icon do we choose to indicate filtering?
3. Is the icon plus padding large enough for comfortable tapping?
4. Do we put the icon at the top, bottom, or floating (mobile/desktop)?
5. What exactly happens when the user clicks/taps on the icon?
6. How will the icon change on tap/click?
7. Will filters appear as full page/partial overlay or slide-in?
8. Can we avoid sidebar filtering as it's usually slow?
9. Do we expose popular or relevant filters by default?
10. Do we display the number of expected results for each filter?
11. Can we use a horizontal swiper to move between filters?
12. Can we avoid dropdowns and use only buttons/chips plus toggles?
13. For complex filters, do we provide search within filters?
14. Do we use icons to explain differences between various filters?
15. Do we use the right elements for filters, e.g., sliders, buttons, toggles?
16. Do filters apply automatically (yes, for slide-ins)?
17. Do filters apply manually on confirmation ('Apply') (yes, for overlays)?
18. How do we communicate already selected filters?
19. Can selected filters appear as removable pills, chips, or tags?
20. Do we recommend relevant filters based on selection?
21. Do we track incompatibility between selected filters?
22. How do error messages or warnings appear in the UI?
23. Do we allow customers to reset all filters quickly, at once?
24. Are filters (or filter buttons) floating on scroll on mobile/desktop?
25. Can users tap on the same spot to open/close filters?