BlueJeans Network IOS Developer interview questions

the first round was through a video call of blue jeans network's product.....I applied through their website...I got a call from HR same day.....The interview was tough because the opening was for R&D department so obviously it was supposed to be tough.I was not prepared for the interview.....but the guy(Navneet Kumar) who took the interview is an awesome guy...he is a knowledge bomb!