3 Interviews (on different days)
1. Technical Recruiter : HR questions with some Technical Interview questions
2. Technical Panel: Interview Questions with the Lead and Seniors Developers
3. HR Head and Leads: Cultural / Behavioral Fit Questions.
4. Offer
One thing that I noticed is that they spend too much time trying to find the perfect candidate. If they don't like an answer to one specific thing they immediately frown (literally) despite it being the correct answer or near the correct answer. They have opened their job ad for at least 6 months now.
My suggestion is that there is no such thing as a perfect employee or
perfect candidate. You might as well be searching forever.