I’ll also add two more, written by my former colleagues:
Ruby Science, a nice catalog of improvements you can make to your Rails app.
Maybe Haskell, a really nice intro to an interesting idea from Haskell. It won’t teach you Haskell, but gives you a great exposure to a worthy concept.
The teachings of Maybe Haskel are easily transposable to Swift. Reading through it made me understand and appreciate concepts that have greatly levelled up how I write code.
Another of hers that I enjoyed (or the other of hers, I suppose she’s only written two books), is 99 Bottles of OOP.
And for any PHP developers here, I’d recommend Refactoring to Collections by Adam Wathan, which teaches developers how to be more declarative / expressive using higher-order functions.