I had two phone interviews and failed the second one. Both interviews used a collaborative text editor for questions involving code. The first interview covered a range of topics. I was asked to name 5 two-letter unix commands and how to find the number of files in a directory and all its subdirectories. The next topic was functional programming. I had to explain what a fold is, write down the type of a fold function (in a language of my choice, not necessarily OCaml). I was asked about tail recursion and tail calls in general. Then I had to write a function returning all permutations of a list (again, in a language of my choice). I was asked if I knew what memoization is and had to write a function that returned a memoized version of a function that was passed in. We then discussed the problems with my implementation (the cache I used would grow larger whenever the function was called with new elements).