So I told the internet to feel free to ask me questions. Here is that collection.

How to interview when you’re hit with something that you don’t know

Say an interviewer asks me “So, I hear that you’ve worked in Java a bit. Tell me about how you’d use lambdas, collectors, and concurrent maps to design a massively concurrent ticket sale system.”

Moving beyond the fact that maybe this isn’t the best interview question, it’s at least plausibly difficult to answer.

Say that this is not a question to which I have given much thought, and not one to which I had a readily-composed answer, and I hadn’t used a java lambda in production code yet and I wasn’t super clear on how collections were different from other things that they could be similar or different than.

I would start with admitting that I don’t know, but in a way that tells the interviewer that I am game to keep trying. “Well, that’s not something I’ve done before. I can try to walk through it. Let’s start with… concurrent maps. You only need those if you’re designing the system such that…”

I would ask questions. “So when you say a java lambda, do you mean that you’re passing functions around as first-class objects, or…?”

If they ask “tell me how many pingpong balls in New York City” I would probably tell them that they’re not doing a good job of asking intrerview questions, because I don’t believe that they can derive valuable information about how I would do at the company from my answer to that question.

What are the kinds of things that I don’t know? Some technical facts. Some theories of design. And of course, things that I don’t know that I don’t know. One of the things that I really enjoy while being interviewed is learning. That, and talking to people about interesting things and hearing about how things are at their places; even if I don’t end up there, knowing about how they do what they do is inherently interesting.

What is a java lambda? What are java lambdas for?

That is a good question and a quick google around did not make it clear to me, and I will probably have to find out for other reasons pretty soon anyway.