Has no complaints about process itself, the 30 min screening interview followed by technical interview conducted via CoderPad. The task was to implement miniscript language. Couple example of statements given. When this statements pass tests, interviewer adds different kind of statements to language and ask to modify your program to handle them too. This is really standard task in computer industry, I've done it many times on the job and there is whole theory and set of tools (parsers) which programmer typically use in practice. However since this is a CodePad - you cannot use third parties libraries. The standard way to solve such kind of tasks is to have a grammar, break down input into tokens and then apply parser. Since the only time you have at your disposal is 45 min, some steps needs to be hacked, so for lexical parsing I used regular expressions and for grammar parser - just branching logic based on first token. The interesting question is what kind of skills company trying to verify with this sort of test? How to solve standard task in very strict time constraints? The task is trivial itself, but all experience made me think company looking for hackers rather than engineers. I am going to skip on further interviewing with Square regardless of interview results which are not known to me yet.