Mock Interviews for Fun and Someone Else’s Profit

Last year I started offering mock interviews for iOS developers. It’s been a learning experience for me and, I think, others. I’d like to share a bit about what me and the 10 folks I’ve interviewed so far have experienced and what’s next.

Through the wonder of the internet, I’ve met (and hopefully helped) folks from all over the world. Once a week I interview an iOS developer from anywhere in the world during my lunch hour. I’ve interviewed people from the US, Canada, Italy, Australia, and more. I currently have another 8 interviews lined up with folks from Greece, Singapore, and Brazil to name a few.

Interviews start with about 15 minutes of iOS knowledge questions that cover a wide range of categories from user interface basics to concurrency. I tell candidates that real interviews will go much deeper on each of these topics. This helps them figure out the sort of things they may be asked in a real interview. Of course, I also explain that interviews vary from company to company. I don’t ask questions about ping-pong balls in boats or busses.

The knowledge portion of the interview is followed up by a brief programming exercise using a shared text editor. I say up front that I don’t care about syntax, but I do want to know whether candidates can solve the exercise and explain their rationale as they go. I explain I don’t care whether the code compiles or if they can remember the name of a specific API since tools help with that sort of thing in a typical setting. I do look for whether they find ways to improve their code or the skeleton API I provide. The exercise doesn’t revolve around a Computer Science brain-teaser or some clever trick, though you ought to know a common data structure or two.

Candid feedback is given as we go and at the end of the interview. I explain what I expect from folks starting out, mid-level, or senior folks. And I leave a few minutes at the end of the interview for candidates to ask questions. Of course, I say “I don’t know” when I can’t answer them.

Feedback from candidates has been positive and most of the interviews went rather well. Interviewing can be nerve-wracking so it’s rather gratifying to hear I’ve helped someone feel more comfortable with interviewing. I’ll keep doing this for at least the next few months.

P.S. Let me know on Twitter if you’re experienced and interested in giving mock interviews. I can share my topics and exercise if you’re an iOS developer. Otherwise, you’ll need to put together a plan of your own.


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