First I received an exploratory call from HR, after 2 days I had the official interview with HR via video call, after a week, I went to the office to attended 2 sessions of face-to-face interviews with HR manager and line manager respectively, the last round interview with the country GM was 3 weeks later. I didn't get the offer end up, and was confirmed by 5-6 weeks later by email. But I still appreciate the official revert, to me it's better than having no feedback .