Python Interview Questions – Senior

This appears to be a fairly arbitrary list of questions, and the categorizations (including the Junior and Middle lists linked at the bottom) are similarly arbitrary.

For example, some of the Middle questions seem to me more things a Junior should be asked, and vice versa. Specifically, it asks about modulus operator in Middle but expects a Junior to identify the key features of Python. I would seriously expect most beginners to have some idea about modulus, but next to no idea about key features.

At any rate, I very much prefer a short list of very open ended or very focused questions with lots of room to grow. Like 3 to 5 questions should be able to fill an hour if they are good questions by my metrics.

For general questions, I like things like "What are the key features of the language?" but I phrase them as "What are your favorite parts of the language? Least favorite parts?"

Those answers are often very telling -- often Juniors will have very shallow answers or none at all for "least favorite".

For specific questions I like things like "reverse a string". Not so difficult that it's a brain teaser, but plenty of room for diving into different approaches and discussing idioms of the language.

Again, these answers are very telling -- often Juniors will only be able to write one very simple version, but a Senior can write several and talk about the trade-offs.

As a CTO of a python shop I would fail in answering a lot of these off the top of my head.

That is why I do not ask any language specific questions in my interview process. Good engineers can answer all of these questions with an internet connection and a few mins of googling.

Asking questions like this is a pretty bad approach to interviewing IMHO. It selects more for people who have googled "advanced python interview questions" than it does for people who actually have advanced skills.

I've found tests designed to depict everyday work to be the most reliable indicator's of a candidate's skill.

It's an ok test, probably some of those are more "googlable" than just having it in memory.

(I find funny the "love for metaclasses" that people consider as "advanced Python" - it has its use cases, but it is a bit restricted. Also DO NOT USE ABC - it's one of those "let's take this Java thing and try to fit it" but it manages to be an even weirder transplant than logging)

> Q: Place the following functions below in order of their efficiency.

This is the test where a good amount of candidates will do well on the coding part but will completely miss the math considerations. Performance will vary a lot depending on the size and distribution of numbers (and none of them consider a trivial optimization that's possible)

> Q: Is Python call-by-value or call-by-reference?

The most dangerous interview question. First you have to establish that the interviewer uses those terms correctly or at least that both of you agree... There's lots of people who know the answer in practice, but never accepted that passing values which are references is not "pass-by-reference".

I've talked to someone who said "this must be just a typo/mistake"... when I pointed out Java is pass by value - in Java spec :-(

>>> Q: Whenever Python exists, why isn’t all the memory de-allocated?

Is it me or this sentence makes no sense?

As someone who interviewed ~60 people for senior JS and LAMP positions, good luck with these questions. When I was assigned to do interviews, I assembled a somewhat similar list of questions, but we quickly learned that we will never hire anybody like that. I'm sure there are unicorns out there capable of acing these questions without the internet, but they all work for googles of the world.