In groups and channels with thousands of members, opening any screen that
shows the member list could briefly freeze the app. The most noticeable case
was the "Chats with members" screen: closing a member's chat and returning to
the list reloaded everyone and stuttered each time.
The app was re-checking every member against every other member while loading
the list - work that grows with the square of the group size, so it got
dramatically slower as groups grew. It now does this in a single pass, so
member lists, @-mentions, channel relays and adding members all stay
responsive even in very large groups. You see exactly the same members, in
the same order - just without the lag.
Narasimha-sc
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