How to make this UI performant? Naively ofcourse its trivial, its a Column of N Cards, where each Card is a Column of M Items Making it LazyColumn of N Cards helps, however, each Card can be unboundedly big (i.e. number of Items is not fixed) Is there a way to make the each item within Card recycleable? Or try to fake it via flattening it into List<ListItem> and adding horizontal ui to each item to make it appear its nested in a parent, when its not?

Have you tried to build this already and have seen the performance issues?

No, just asking whats the go to thing, as I understand scrollable column as equivalent to ScrollView, where all ui elements are in memory, which doesnt scale since I can have N items, and making it recycleable is my instinct wrong assumptions?

I’m not sure, but I would try it out first? Deep hierarchies are handled better in Compose I think, so it might not be as slow as you anticipate. But I’d try it first.

I dont follow. Is it okay to have Column of 1000 items? I thought its what LazyColumn is for

Oh I don’t think so - I was thinking you’d work with all LazyColumns

yea but how, is it a LazyColumn of CardGroups, or is whole screen on big LazyCoulumn I dont see how to do the latter, while each item looking like its nested inside a card group

I would start with making the lists that benefit from recycling / virtualizing behavior to be LazyColumn/Row. Sounds like those are the columns in the Cards and the cards themselves. Then for the top-level column and row of cards, use just Row/Column.

Are you sure about that? That UI can be N cards tall and each card can as well be N items tall, i.e. in theory you could get just 1 card, with 100 items in it And me being a Compose noob, this worries me, as I now imagine 100 Views in memory at once (compose equivalent of it) Which I believe would lag a lot to layout

It could but I wouldn’t be sure unless I tried since deep hierarchies are handled differently in Compose compared to Views. Also, from a UX POV it seems the user would have issues navigating through this many items on a single screen? That is why I advised to step back and even rethink the design, which can in turn simplify the implementation.

Not yet, I just seen the Bots app ad where the screenshot is from and I remembered I had to work on such UI in the past and it was a royal pain in the ass to do the grouping performant. Twitter threads ui is also a similar issue But is this really about depth? Its just a list of cards where each card is list of items, so 2 levels. I was worried about the total item uis in memory, but yea I dont see how Compose does stuff yet thanks