Be aware they are into wasting your time, I made a mistake didn't ask for my $800 - $1200 off work compensation upfront before I made a trip for an onsite interview, I thought its a descent company, until I met their "iOS Developer" who had setup an "I don't want you to be hired" question, the question had nothing to do with iOS frameworks, Swift or Algorithms, he asked me if I can come up with a solution similar to what he came after god knows how many days he squeezed his brain, One thing you should not ask a candidate is a question about what you spent days and weeks to resolve and its specific to the company business logic, you should put the problem in a general content that could be patterned with similar general solution in CS and the candidate relate to that. Their developer was the least knowledgable developer I have ever seen, the project he had setup was just a single view application with 50 lines of sample code in an Enum about their business logic, but the Unit Tests didn't work it was showing and error that it can not find XCTest frame work so he had to put his unit test in the viewDidLoad !!! Another question he wanted to ask was that this single view app is ugly and how can we make it more beautiful ? are you serious ? I am not a freaking UI designer, although I've been working over 10 years since iOS ever came out so I had some ideas for UIs, but when he ran the app nothing materialized on the simulator !!! there was only a white screen, I jumped into the Visual debugger and he looked at the view hierarchy and he said uh okay okay I know what is going on and he said I have another interview and have to go and he darted out of the room with his sidekick. The whole time another kid was sitting in the corner of the room busy with his laptop typing away and oblivious to anything going on, I guess he was the observer to make sure they have fair interview, sure they got that right. what a joke. I interviewed with two other iOS developer to get to this one and they both had thumbs up for me, expect this guy who had the least knowledge of the two others, he had no intension of giving thumbs up because he already had my resume and I guess got concerned with the apps I have in the app store since 2011 and based on what I see in his coding in that sample code he was one those developers who has no concept of object oriented or clean coding, since he had written most of the code in an Enum I've seen projects that developers had written most of their business logic in one gigantic enum with a size of 2000 line of code all in one enum, and they are afraid if some one with higher knowledge comes to the company is going to blow the whistle of the what a swamp is there called Venmo app. :) Make you decision.