I'm wondering if team size is what makes slack such a pain for many posters. Slack is great for my 8 person remote company. I keep notifications off for channels that aren't directly related to my development responsibilities, but I value having access to them for review at the end of the day so I'm aware of what is happening elsewhere. If I need a long stretch of uninterrupted development time, I turn on Do Not Disturb and everyone knows not to override this unless there is an emergency.