Extremely tough, demanding and unpredictable to ensure the right level of talent is employed - it is the same as the Google process with several phases which focuses on on the core roles/ responsibilities of the role and your problem-solving capability. You will probably find this is a 5 week process from start to end depending on interviewer and other candidate availability
In summary (for a non-tech role):
1. Interview phone screen (20 min discussion about your experience, motivations and role fit with the recruiter)
2. Manager VC screen (30 min interview with the hiring manager or experienced colleague, mostly around culture fit and core competencies of role - make sure you know the job description and get tips from your recruiter).
3. Full loop (this is generally on-site and will involve 3-4 interviews with different people on a 121 basis who will test out different competencies. Expect mostly problem-solving scenarios which will be linked to the position you applied for - such as: you are working in the google customer service team and someone's account has been hacked, what would be your first steps...etc)
4. If you pass, the recruiter, hiring manager and senior management will review your interview performance and agree on a suitable package.