I can't tell you exactly what questions the employer will ask, but I can share with you the two main issues that person will need to address in the interview process.
First, the employer will need to quantify your skill level with the specific technologies employed within their IT department. Be prepared to cite detailed examples of the kinds of projects that you worked on in previous positions. Be sure to include challenging situations and how you dealt with them, not forgetting what you learned from the experience. Your skills may be put to the "test," and I do mean test. Some companies are using written or online testing tools to accurately quantify your technical aptitude. Be sure to address your technical concerns by asking your own questions. Start with what kinds of platforms they're working on, what are they're long-term goals, how is the company technologically positioned against the competition, how do they keep employees current on new technologies.
The interviewers second main objective will be to decide how you'll fit in with the existing team and will you be able to contribute to the group's goals. These questions will be focused more on your "soft" skills, including interpersonal communication abilities and business acumen. The interviewer will want to know how well you've worked with people in previous jobs and your thoughts about what the user's role was in the scheme of your job.
One last thought: A good way to summarize the technical interview would be to put yourself in their shoes -- what would you like to know about the person you'd be hiring to run your systems.
This was first published in February 2001