Zillow Software Development Engineer, interview questions

1st phone interview - two problems, reverse the order of words in a sentence and the second one 4 numbers are missing, find them. 2nd phone interview - traverse a binary tree and append the values to a string, use the string from part 1 to reconstruct the tree, unfortunately it's impossible to reconstruct a binary tree with only post traversal, however you can reconstruct a binary search tree At the end I received an email telling me that they are looking only for seniors.