# Tweet by [@keefmoon](http://twitter.com/keefmoon) on 2017-01-25 08:36:57 > [!INFO] Archived from [original tweet](http://twitter.com/keefmoon/status/824174202777387009) "handler is executed on a UIKit-provided queue, and not necessarily on your app's main queue" is this pattern new? UI safe, non main, queue? https://t.co/ydm9H62pC1