An HR will give you the first phone call. She will go through a list of very basic tech questions and you should make sure you say the keyword of the answer because she just probably checks your answers against the ones provided by their developers. The second phone call will come from an experience dev. He will first ask you to rate your skills on several language, then try to poke your limit on the one you are best on. So get prepared. After the phone call, he will give you a code test which is about implementing operations on a data structure with designated time complexity.