Align Technology R&D Engineer interview questions

They had several steps in the interview process. Step 1: HR Screen - Simple. Went over the resume and asked why I was interested in the position. Had me write an email with answers to 5 different questions, along the lines of Most challenging thing that I ve done in the recent times, what I'm most proud of.. etc. Step 2: Phone call with HR - more of the previous step. Step 3: Technical Phone Screen with Project Manager. - Again discussed resume, and past experience and what I look forward to doing at Align Technology. Also, a couple of technical questions were asked. They were pretty simple. Step 4: Skype interview with the Senior Research Members. They went over my experience and what I am looking forward to doing at Align Technology. Then, they asked several technical questions regarding aligners and how they work. Forces and moments required to move the teeth in a specific direction, free body diagrams etc. It was not easy for someone who has not worked with aligners in the past. Overall interview experience was ok. This was the last step in the process for me. I was told that Step 5 would be direct interview at the company. However, I got a rejection email from the HR 5 days after my Skype interview.

The entire process was done very professional and efficiently