Anyone interested in doing more complicated questions during the phone screen should check out https://coderpad.io https://coderpad.io - you get a live REPL or

Anyone interested in doing more complicated questions during the phone screen should check out https://coderpad.io https://coderpad.io - you get a live REPL or compiler (depending on whichever language you're using), and can run code instantly from your browser. The best part is the environment is shared between you and your candidate, so you can both see the code being written and execute, live.