[stuffedBelly]

for interviews I'd say even straight dumping data into the file system and retrieving later when the user needs it would be a somewhat valid approach. It's more important that the candidate is able to explain the reason he choose this approach over holding everything in memory (writing/retrieval overhead vs. memory limitation, etc), given the data size/structure of the assignment.

If candidates reason well about design decisions of their implementation, perfect or not, it at least tells me they are reliable developers who do not jump into coding before thinking carefully.