Duolingo Ios Engineer Interview Questions
& Process

First, I was asked to talk about my background and why I want to work for Duolingo. Then, there was a take-home assignment where I had to pull an unstructured JSON document, parse it, and load it into a game. I have no idea how I did on this. After spending hours programming, following Duolingo's own design guidelines, creating app icons, documenting, and testing, I was rejected. When I asked for feedback, I was told: "Unfortunately due to confidentiality reasons and company policy, we are unable to give feedback at this time." I'm not sure why this information is confidential. I guess my advice is to make it really good, but there are limited guidelines. If you don't care about your time and want to work for a company that shares that sentiment, then definitely apply.

The initial screening was okay, but the rest wasn't worth my time. They gave me a take-home coding assignment where I had to fetch a file, display its contents, and run a game with a custom UI. The instructions were pretty vague on file storage and UI implementation. The screener estimated 10-12 hours for completion, which it took me to do it properly. A quicker, less organized approach would be about 4-5 hours. After all that time and waiting, I just got a rejection message. They wouldn't give any feedback, which I find really disrespectful, especially after asking for 10-12 hours of work. In my 8 years of experience, I've never seen a company care so little about a candidate's time. This is why I'm writing this review. If they treat potential employees like this, who knows how they treat current ones. Seriously, just avoid Duolingo. Look at companies like LinkedIn or Pandora that have solid technical interviews that at least offer some value. I've worked for some and been rejected by others but still learned something. Don't waste your time here.

The interview process included a recruiter screening, followed by a technical screening. Then there was a team match phase. After that, there were two technical rounds: one focused on LeetCode-style problems and another on system design. The process concluded with an onsite interview.