[eli]

Except if you read the whole post, he ran into a previously undisclosed explicit user limit. The client was crashing. Slack ideally should warn you if you have too many users, before the point where the client crashes and the backend fails to send messages.

[cloakandswagger]

Even if they hadn't, the 10k message limit is well publicized and would have forced them into an insanely expensive pricing model.

Slack's pricing model and the ad copy of their website makes it obvious to me that it's a communication tool intended for small teams, not a chat room for thousands of users.

[briandear]

But who runs a chat with 5000+ users? The signal to noise would be insane. If each user posted 1 message per hour, that's 5000 messages per hour. For a group that size it seems like Twitter makes more sense. I can't imagine 5000 people needing real time communication. Kind of the mother of all edge cases for a team chat service.

[detaro]

I don't think they are talking about 5000 users chatting in one chat room, but about 5000+ users having a common place to talk to others in small groups and maybe read announcements in a main channel.

My university uses Slack, and the "main" rooms see a few posts a day, but there are tons of small groupchats and DMs.

[pcr0]

It's usually 50-200 users online at a time, and out of that maybe 20-50 are chatting at least once a minute, so no, not 9000 users actively chatting at once.

[Cthulhu_]

There's plenty of IRC servers (which is probably the closest analogue to Slack) with more than 5000+ users. Sure, most of them have a #general channel, but nobody will see that one as the main channel; most will go to a more topical / relevant channel. That's how IRC works, that's how Slack should work.