Multiple Stream Deck devices can be connected to a computer and work at the same time. 

Can multiple of the same Stream Deck be used at the same time?

Yes. Any combination of Stream Deck devices can be used at the same time. 

Can multiple different Stream Deck devices be used at the same time? 

Yes. You can mix and match any number of Stream Deck devices. 

Do Stream Decks interact with other Stream Deck devices? 

Yes. Certain actions allow one Stream Deck device to control another Stream Deck device. 

For example, a Stream Deck Mini can be used to change the profile of a Stream Deck by using the switch profile action.