principle-product-designlisted

# Product Design Principles ## Usability Heuristics (Nielsen's 10) Every user-facing component must satisfy these. Violations block progress. | Heuristic | Rule | Common Violation | |---|---|---| | **Visibility of system status** | Users always know what's happening | No loading indicator during async operations; silent failures with no feedback | | **Match between system and real world** | Use language and concepts users know | Developer jargon in UI labels ("null", "undefined", "404"); unfamiliar abbreviations | | **User control and freedom** | Provide undo, cancel, and escape routes | Destructive action with no confirmation; no way to cancel an in-progress operation | | **Consistency and standards** | Same action, same result, everywhere | Button styles that vary across views; inconsistent terminology for the same concept | | **Error prevention** | Prevent errors before they happen | Allowing invalid input submission; no constraints on date ranges or numeric fields | | **Recognition over recall** | Show options, don't force memorization | Hidden navigation requiring memorized paths; no search/filter on long lists | | **Flexibility and efficiency** | Support both novice and expert users | No keyboard shortcuts for power users; no progressive disclosure for complex forms | | **Aesthetic and minimalist design** | Every element earns its place | Cluttered layouts with competing visual weights; information overload on a single view | | **Error recovery** | Clear error messag