Gainlo (http://www.gainlo.co/ http://www.gainlo.co/) does mock interviews with actual Big N / unicorn developers for a price. Triplebyte (https://triplebyte.co

Gainlo (http://www.gainlo.co/ http://www.gainlo.co/) does mock interviews with actual Big N / unicorn developers for a price. Triplebyte (https://triplebyte.com/iv/afyYdFu/cp https://triplebyte.com/iv/afyYdFu/cp , referral link), if you can make it to their final video interview, will also give you full feedback whether or not you pass, for free. They don't do whiteboarding but they do live coding and debugging. There are a few general tips though... the biggest of which is to talk out loud. They're not necessarily wanting a full solution to the problem (although it helps); the interviewer wants to know how you think, whether or not you can code decently, and if you test. (You prove the last part by running an example through your code while talking about it to find and fix any bugs.) Check out Cracking the Coding Interview (https://www.amazon.com/Cracking-Coding-Interview-Programming-Questions/dp/0984782850 https://www.amazon.com/Cracking-Coding-Interview-Programming...) for more of this. It's a very good book. Pairing its problems with an actual whiteboard and a timer is a close approximation to a real interview.