I applied through a staffing agency. The process took 2 weeks. I interviewed at National Energy Services (Milton Keynes, England) in Nov 2015
Interview
Stage 1 is a telephone interview. Stage 2 is a face to face interview at company offices in a meeting room and consisted of questions, querying code and writing unit test session. Staff seemed polite. Don't expect them to get back to you if they are not interested, even to provide feedback which shows lack of respect considering you take the time to take their interviews.