I applied online. The process took 1+ week. I interviewed at Opower (San Francisco, CA) in Oct 2014
Interview
I was first contacted by a recruiter at Opower, who reviewed my resume and coordinated interviews. I had phone interviews with two Opower senior engineers, neither of whom asked me technical questions.
I applied through a recruiter. The process took 2 weeks. I interviewed at Opower (Arlington, VA) in Jan 2015
Interview
Give a brief introduction of yourself and then three different people from different team will give you questions, like your working experience, your courses at school. After the first round, you will me the director of your team and he/she will introduce what they focus on. If you can enter the last round, you will have chance to meet all the teammates and they will give you a average comments. Anyway, the interview process is average difficult. I was not applying a tech position, so I did not have programming test.