85
list virtualization
Render the rows on screen, not the ten thousand off screen. Recycle views.
What is list virtualization?
Virtualization mounts only the visible window of a long list, plus a small overscan, and recycles rows as you scroll. A map of every row mounts every row. Memory and frame time die there.
Why does list virtualization matter when vibe coding?
Models `.map` a feed into views. The simulator has 20 items. A real inbox has 5,000. Name a virtualized list or the phone gets hot.
How do you do list virtualization?
Any list that can exceed a screen uses a virtualized list with a stable key and a known row height when you can. Do not virtualize a form of six fields.
How do you ask a model for list virtualization?
Virtualize (list). Do not map every row into the tree. Stable keys. Avoid variable-height surprises if you can measure. No virtualization for a short static list.
What goes wrong with list virtualization?
Virtualizing and also fetching every row into memory. The window is the view. The data still needs pagination.