I had multiple rounds of phone interview (atleast 6) and you don't hear from them until when they want to schedule another round. The HR person will just be bombarding you with calls every 5 minutes the day before they want to schedule an interview, hoping that you are available 24*7 for them. She will leave a message to ask you to call her back, leaving no additional message of why they want you to call back. No email correspondence either. They will sincerely ask your availability and say that they will schedule the interview at that time, but they wont get back to you or apologize for not calling. Your time will be lost in blocking that day for this recruiter / waiting for their call, while the time could be better spent on something else. The HR person does not even know what job responsibilities the candidate needs to have. They only know what position they are hiring for. It is better that you ask the interviewer from the project / client all these details and see whether you fit in the role.