The interviewer was very polite and told me this is probably the most demanding job at Tesla, especially at this time of the company's state when they're ramping up the production lines for Model 3.
I was intrigued and went to second round interview, and it eventually led to an offer. That is where things got interesting. Tesla needs to invest heavily in their Module engineers. The pay package was extremely disappointing and I am not willing to let go of the golden years of my life (late 20's) for this kind of a job unless it is heavily incentivized. I've had similar demanding job offers from oil companies, but at least they offset with a very compelling pay package (15% Alaska bonus, 4 weeks off, presumably amazing yearly bonus).