After applying, had a 15-min phone interview with an internal recruiter. She seemed to be testing whether I knew much about the company or the industry, and whether I had knowledge about energy efficiency. After that I was passed on to the main team, where I had 5 30-minute phone interviews. I had 1 case interview involving a strategic challenge facing Opower and the rest of the interviews were about my background, what i could contribute to Opower, how I thought about Opower's challenges in terms of future growth opportunities. You should absolutely know the SWOT analysis of the company and be well versed in the opportunities and challenges for the company. You should know the website (and blog) inside and out, and you should be prepared to talk about Opower's business model and changes you would want to make.