I have about 1.5 years working experience and am an iOS Engineer.

The interview started off with just general questions about my experience. I went really low level and detailed with my responses. I spoke about my designs of a Networking and Translation Layer, a garbage collector I wrote for Realm, and general full stack iOS development. After that, he asked about some iOS concepts like threading, memory management, etc. Then the interview was over. No actual programming question. He said that he knew I could code. In my responses I did go about my implementations, mainly with thread safety and queuing (the apps that I work on are very CPU intensive). I am not saying that all technical phone interviews do not have a coding question, I am simply stating my experience.

Couple days later I got the email saying I did well and that they wanted to set up an on-site