Did you think they use group Messages rooms for comms?
I've got to imagine most of the big companies do at this point. Amazon uses Slack as of about a year ago.
google tried to prevent teams from using slack "for security reasons" but then deepmind got an exception, and enough people had to join slack groups for external work collaborations, but I don't think the leadership ever explicitly sanctioned slack as an officially supported internal mechanism.
The vast majority of team communication at Google goes through Chat. The only Slack usage I know of is acquisitions (who are encouraged to move off it) and interaction with customers/partners.
worked there for 12 years. deepmind uses slack. many other teams do to. Unofficially.
They’ve been on it for a couple of years.
Apple probably even uses Windows, for those 3D modeling workstations.
"Made in China. Designed in California on a Windows PC."