01
Own the paint path
Keep painting deterministic, avoid hidden state changes, and let the component lifecycle request repaints.
02
Compose deliberately
Treat transforms, alpha, filters, and buffers as ordered operations whose intermediate results can be inspected.
03
Measure interaction
Profile repaint regions and event handling while the demo is moving, not only while it is idle.
Working rule
Make the next measurement cheaper than the next argument.
Keep a minimal reproduction close to the observation. Change one variable at a time, preserve the failing path, and prefer before-and-after evidence over a broad rewrite.