Rakuten Software Developer interview questions

First took an online coding test. Then got an email to come in for an onsite interview. Met with 4 different interviewers from 2 teams (big data and user) and got extensively asked about projects as well as quizzed on some concepts. Questions included basic inheritance understanding as well as some design and database questions. Also got told that there is free catered lunch and commuting is payed for.

I went through a very lengthy and tiresome interview process of 4 rounds as most everyone went through but it dragged a bit more than 2 months. 1) Online technical test and video pre-recorded questions 2) Technical interview with Direct manager/Team Lead 3)Technical interview + Behavioral interview with Section Manager 4) Essay writing on 2 Rakuten books written by their CEO and followed by final interview. The problem is I didn't expect the final round to be still a technical interview and in fact the toughest technical interview in all 3 rounds. The first 2 technical rounds were pretty easy. It's ok to fail candidate but I feel Rakuten doesn't respect candidate's time and effort. Such technical challenges should be put up front rather than letting me even go through essay writing, put aside all the waiting time in between.