I take it you are being interviewed, you are not the one asking the questions. If I was on an interview panel the questions I would ask an entry-level designer would be to gauge how familiar they are with the C3D workflow; can they create alignments, surfaces, profiles, and corridors and do they sound competent at it or can they list direct experience (i.e. "At my last job, I created x number of design corridors, with their associated profiles and cross-sections"), or do they sound vague about any part of it, or they recite a canned answer ("Well I know how to read the help files, and I'm quick to learn!"). After that I'd sound them out about deeper things, do they know how to create styles from scratch and also create styles based on existing styles; have they created custom code sets; are they familiar with manipulating feature lines (describe two ways to change the elevation of a PI point, and explain one reason why a PI might have its elevation locked). Also can they get quantities from their corridor using the materials lists. Maybe ask what the difference is between the datum surface and the top surface, and how each is used to compute quantities. If they sound experienced at all these, I'd delve a little deeper, and ask them for examples of how things went wrong, and what they did to correct it, or how they double-check the results they get from C3D using manual methods. Maybe ask them if they have used Pipe Networks, and give some examples of how. On your side as an interviewee, I'd ask them some questions too: How rigorous and well-defined are their CAD standards, and how are they enforced, do they have a CAD administrator, do they have on-the-job training or mentoring, either formally or informally for teaching their processes and standards to new employees, and do they have a formal QA/QC program. Trick question for that last one: If they say "Yes", then ask them to define what the A and the C stand for, and what they really mean. This is how you tell if they really have a QA/QC program, or if it's just a buzzword they throw out there when asked.