As soon as I read this sentence from Michael Ilseman...
You can think of String as an artisanal enum, hand-crafted using traditional bit-twiddling techniques in order to produce compact and efficient code.
… I knew I was going to enjoy the rest of the article. You don't necessarily need to know the internal storage mechanism of strings in Swift to write good iOS apps, but it can't hurt to have a passing knowledge of these changes.
State machines are a potential answer to a great number of problems in software development. Can they be the answer to the problem of displaying multiple different states in a view controller? Of course they can! Let Vadim Bulavin explain.
Keith Harrison on dealing with an age old problem using child view controllers and self sizing views. He even goes into detail about how technologies like dynamic type will affect your layout. If you're interested in more Auto Layout wisdom from Keith, you may also want to check out his book on the subject, it's excellent.
Note: For full disclosure, I received a review copy of the book a few months ago.