A prerequisite for the IT staff selection: to notify about the call in advance, because tech people don't like unexpected calls. They value their private space.
Interestingly, in 90% of cases, an interview with a candidate scheduled for 9 a.m. (at the initiative of the candidate himself) is canceled or postponed. Therefore, in the case of the IT staffing, specific recruitment methods, such as online recruiting, are urgently needed.