Interaction Latency
Time from user tap to action successfully completed.
When to Use
- "Add to cart" button tapped → cart updated
- "Submit" button tapped → form processed
- "Like" button tapped → state changed
- Any tap that triggers async work
Measurement Pattern
TAP → START_SPAN → [async work] → END_SPAN
- Capture tap timestamp
- Start span with operation name
- End span when action confirms success
- Include success/failure outcome
Key Thresholds
| Rating | Duration | |--------|----------| | Good | <300ms | | Acceptable | <1s | | Poor | >1s |
Implementation
See references/ui-performance.md (Entry Point Latency section) for platform-specific code.
Common Mistakes
- Ending span on API call start (not completion)
- Not tracking failure cases
- Missing the tap timestamp (starting late)
Related Skills
- See
skills/navigation-latencyfor screen-to-screen transitions (vs single-tap actions) - Combine with
skills/user-journey-trackingfor friction detection on key interactions