The initial contact and interview were generally positive. The phone screen was a good discussion and the process was relatively quick to set up the on-site interview.
However, I never heard anything at all after the interview, which leaves me with a negative impression of the recruiter, the process and company overall. I'm sure Nest has no shortage of candidates; at the same time, I have interviewed enough candidates at my current company to know that it's just a good practice to treat people with respect, even if the decision is ultimately that someone is not a fit. That same candidate may ultimately be a customer, and a negative impression of the company may impact someone's decision on whether to buy or recommend the company's products, or even whether to refer other qualified candidates for the role.
The recruiter also reacted very strangely to several of my questions during our initial conversation. All in all, not sure what it's like to work there, but I'd be concerned based on my experience of the interview.
With regard to the interview itself, I don't remember any questions that were particularly difficult. Several people asked questions indicating that the development process is really more waterfall than Agile.