Monotype Senior Software Engineer interview questions

The interview process has 4 rounds. 2 Technical rounds (1st is 1:1, 2nd one took by two people), 1 Manager Round, 1 HR round. Once all-round cleared, First Background verification took place then they gave the offer letter.

First Telephonic - Introduction call for role and responsibilities specific discussion Second F2F with Lead Engineers - Quite positive and generic discussion on Algorithms and Data structure. Third F2F: Engineering Manager - Architectural discussion of current/previous product. Fourth F2F: Frontend Lead - Discussion on UI architecture. [These 3 rounds took the whole day, waiting time was higher than expectation] After all the rounds, HR approached and said she'll call for the documents and other next steps. [Next Day] She called and asked to share the documents. [After 2 days] -She mailed the references mentioned in their documents about the background check, and received the feedback. [After another 2 days] -Someone from the team called and said your feedback is positive but you'll have to wait for another 2-3 days for the offer letter. [Those 2-3 days never came and I don't even know what went wrong]