Interesting. IBM adopted Slack just fine, back in 2016. I believe they've got at least 100k employees in their Slack workspace. Not sure if it's Slack or IBM doing the hosting/scaling for it, though.
How many Uber drivers are there? Also, don’t forget that slack has an API so write loads can be very different regardless of user count.
Was this chat app for external contractors as well? Highly doubt it.
> How many Uber drivers are there?
None, they're all independent contractors.
That’s still an Uber driver. They’re literally being contracted to be so.
There is a cultural difference between Uber and IBM which would explain why Slack didn’t shown its limits at IBM: Slack people belong to a startup which typically wouldn’t mind get everything done in a chat; whereas IBM is a 100+ years old company where everyone has to fill a paper form and managers type with two fingers (Source of this specific example: I’ve worked with IBM consultants with one of their products). Chat apps do not play the same role in each.