I applied online and I got an email from HR a week later. HR wasn't the quickest about responding to emails, but I eventually scheduled an interview with the head engineer. She mostly asked questions about data structures and algorithm efficiency. The questions weren't unreasonably difficult; you just have to make sure you know how your chosen language works internally.

I got an email from a recruiter asking me to schedule a phone interview. After the phone interview, I was told the position I had interviewed for had filled and they would consider me for a similar position at a different location. They flew me onsite and there were 5 interview rounds with different senior software engineers and the hiring manager. The HR told me I should here back in 24 to 48 hours about the interview feedback. It has been 2 weeks and I haven't heard back from the HR. I have emailed the HR and called them but there is no response. Extremely unprofessional and poor HR response.