At my org, we don’t have phone numbers for each other. If it’s urgent, just keep pinging them on Slack until they respond, and ping multiple people who can potentially help. It’s incredibly rare that you’ll ever need a specific individual on an urgent basis, almost everything can wait until tomorrow morning, and even emergencies can be handled by more than one person.
I respond to Slack messages by end of day. If someone has something urgent they will call me (on the work number, of course).
At my org, we don’t have phone numbers for each other. If it’s urgent, just keep pinging them on Slack until they respond, and ping multiple people who can potentially help. It’s incredibly rare that you’ll ever need a specific individual on an urgent basis, almost everything can wait until tomorrow morning, and even emergencies can be handled by more than one person.