I had a fantastic experience interviewing with Culture Amp, and was blown away by their communication and professionalism throughout the process - I cannot speak more highly of my experience!
I started the process by applying on the company site (via a job posting on LinkedIn) and within 24 hours I was contacted by HR to organise an initial screening call. The screening call was 15-20 minutes with questions focussed on why Culture Amp and what you're looking for next in a role etc. Scoping out if there could be a potential fit.
With that stage going smoothly, I moved through to first round interviews, which was with a Lead PM (the direct report for this role). This was largely focussed on behavioural type questions, e.g: Tell me about a time when...
Following that stage you move into a take home case study task (~4 hours work) followed by an interview to present the case study to a panel of 3 interviewers. This consisted of other team members you'd be working with (Lead PM, other PM's, Designers), and after the presentation you're asked a range of questions related to your case study.
The final round was with 2 other potential future team members (in Tech, Delivery, People Scientist roles), and it's focussed around the way that you work - some more behavioural style questions in this stage.
I received a call the same day as my final interview letting my know that the feedback was positive, and then the following day received the official offer. Talk about speedy!
For a PM role, it's a very reasonable process (pretty standard to have ~3 rounds and a case study as a PM), but what sets Culture Amp apart is their fantastic communication at every step of the way. Following each stage I had an incredibly prompt email from HR advising me of the next steps, what was involved, what I can expect and who I would be speaking with, as well as even providing some online resources to learn more about the company.
I've personally never had a better interviewing experience, and just as you would expect from such a fantastic company, every single person you met along the way was as kind and intelligent as the last - definitely helps to quell those interview nerves quickly!