Nothing is working tonight (13 June 2018)

No… There certainly could be SmartThings Cloud issues, but, in such a case, there are usually many more reports. Of course, it would be really great if we could trust https://status.smartthings.com to be up to date and accurate. It currently says “all operational” … no surprise.

The SmartThings Cloud has 5 major slices (“Shards”), and I am on the original (graph.api = NA01). My home is working fine with sub-second response (I have a Hub V1 with no local execution).

Knowing your Shard is helpful, as problems are sometimes isolated to a specific shard, and thus only affect a portion of customers: