Connecting Multiple Incoming Internet Connection

In my workplace, they have service from multiple ISPs. When one of the ISPs goes down, users have to manually switch to a different ISP. Some LAN points are connected to some ISPs only. Each router that has an incoming ISP has a wifi as well. And in case of a service outage, user has to switch Wifi.

I am sure there must be a solution that the entire workplace is wired to same LAN and all ISPs are connected to same LAN, and in case of a service outage, there should be an automated switching , without letting the user know what hepend.

I do realize that when that switch happen, the public IP will change when user connect through a different ISP. I am willing to ignore that part.

So the question is how do you guys generally connect multiple ISPs.