IT professionals build, design, and maintain the systems that handle storing, sending, and retrieving information. Employers are looking for individuals who are able to systematically solve the tough and unusual problems that arise in the field. Expect to be asked many hypothetical questions that will assess your thought process when dealing with complex problems.
How would you store data to calculate performance during a conversion to a new system? would you store the performance calculated by the current system or would you use the new system to calculate performance from account inception with new data?