The three topics you propose are hard to teach, maybe hardest. You have to shove the entire thing in the head at once to do much of any of it. By entire thing

The three topics you propose are hard to teach, maybe hardest. You have to shove the entire thing in the head at once to do much of any of it. By entire thing I mean architecture, coding, unit testing, exception handling, and especially debugging. You can't leave one out and have a successful assignment. Lets compare with a graphic library; you can learn the DrawRectangle API without learning the DrawLine API. Not so with Concurrent. Some kids won't understand the debugger (if any LOL) Some kids will get stuck at coding. Some kids will have weird conceptual hangups. All the kids need to learn all of it all at once. Its a big chunk. Same problem with Network. Pre-reqs are seen my uni admin as a way to restrict tuition income, LOL. You can't assume the kids are up to the level of a Net+ cert or even an A+ cert. Its a big chunk all at once. See above, you "probably" can't do network "correctly" unless you async it. Does the class system even have a pre-req that includes the concept of a TCP/UDP network port? Its just a HUGE topic to inject all at once. When people say DB they are usually unclear. I took a senior level DB class and learned Codd-Normal forms and all that which makes SQL query writing pretty easy. The problem is your interns aren't graduated seniors yet and they probably eliminated that class from the curriculum because "No-SQL movement" or whatever new hotness caused a distraction. I think you'd be a better logical thinker about organization of data if you know your Codd-Normal forms or have at least been exposed to the general concept. But other kids want to learn mobile app dev or frontend or whatever new hotness. Finally a lot of uni work is filtering. Must be smart enough to learn up to this level even if you never use diffeqs again. So the kids you're interviewing don't know anything useful, but they're smart enough to learn, and it'll turn out OK, probably.