on Fri May 15 2020
RESPONSE : Paint in less than 100 milliseconds. An action for example is to click on a button to trigger paint.
ANIMATION: Each frame completes in less than 16 ms. Example is smooth scroll or drag.
IDLE: Use idle time to proactively schedule job. Complete the job in 50ms chunks ( as user might interact in between and to deal with that )
LOAD: response goal during full load. Get first meaningful paint in 1,000 ms.
Do not obsess over numbers at first. Try gradually improve performance over time, say 10% towards the goal.