Goes without saying really, but asking about company culture always gets interesting answers. I also like to ask them about one of their proudest release and what it took to reach the final version.

Everyone's posting questions from the employer's point of view, but he's asking for question to ask the employer.

I usually ask about their process from the brief to the final product, the way the teams are structured, and where I'd be in the process.

i got asked how i would design an ATM for a large national bank in a recent interview. i think questions like that, where you ask candidates how they'd redesign something that's familiar, are really interesting because they test how well the candidate thinks on their feet, and you get a good idea of what their process is like. i don't think i did too well on the question, but i did end up with an offer!

I found that asking them their thought process behind a couple of design decisions in a flagship project they've done reveals a lot (if you're speaking to someone who was involved) and gets you some interesting back and forth

Can't remember where I heard this but I like the idea of this for an interview question/riddle:

Suppose you had 8 billiard balls, and one of them was slightly heavier, but the only way to tell was by putting it on a scale against another. What's the fewest number of times you'd have to use the scale to find the heavier ball?

I don't think this even has to be about getting the right answer. It could just give you an idea of the candidate's critical thinking and deductive reasoning skills. Plus, if they get excited about the challenge, that's probably a good sign.

Great question. I like interviews to stay focused on what the employer can offer me - and what I can offer them.

I'll have a bucket of questions based on research about the company itself, but I really want to know about culture, process, and benefits. Things like: How is the team structured? Are the product(s) design centered? Who are the primary clients/stakeholders? What's the typical career path for a designer here? Do you provide training expense - also, what about conferences? Etc.

I want to know if it's a place where I can learn and lead as a designer.

I find you can really get a feel for another designer by asking them slightly more casual things like "What's your favourite album cover", "Who's your favourite designer?", and "Which is your favourite rebrand from the past 5 years?".

The last one especially will tell you if they pay attention to the industry in general.

I have always though design challenges

But as far as interview questions. My favorite has been: "Explain how you would go about designing an elevator system for a building with 100 floors"

Talking about past projects is nice if the person has tons of experience but for those with less than 5 years, don't bother.

Its best to uncover their thinking abilities, especially with product design.