The whole process took two weeks, and there were four rounds of technical discussion. Every round of the interview was positive, and after the hiring manager round, I was asked to wait for three days for updates. I waited, and when I called HR, the response I heard was, 'It's on hold, and you lacked on the design question.'

I just wanted to let you all know that there were no design questions.

This is purely unprofessional conduct by Rakuten. After several rounds (four) of interviews, which were all positive, simply putting a candidature 'on hold' doesn't make any sense.

There should be justified and actual reasons provided to the candidate in such a case.

First and foremost, there were no communications sent from the company's side. After several calls, HR simply saying, 'Your profile is on hold' or 'Your design skill is not that good' proves the lack of transparency in the interview process.

If the stated reason was real, I wanted to know what design questions were asked and what I lacked in my provided solution.

I deserve to know the explanation, and I hope this is not a tendency of Rakuten (online platforms are full of such reviews).

I would recommend never ever give your valuable time to Rakuten. I have seen this happening to multiple folks out there who interviewed with Rakuten.

1st round

1. Multithreading
2. Asked to implement your own DS which supports insert, remove, and getRandom with O(1) time.

2nd Round

1. API design.
2. Multiple questions on Microservices.
3. Elasticsearch questions.

3rd Round

1. Deep dive into Microservice architecture.
2. ELK stack questions.
3. Native cloud questions.
4. Java questions.

After all rounds were positive, the last round was managerial:

Q1. Multithreading question. Q2. Implement BST with unit test cases with a Docker container running.