Rakuten Senior Interview Java - 3 YOE
Summary
I completed four interview rounds at Rakuten for a senior Java position, covering Java/Spring Boot fundamentals, a LeetCode Rotate Array problem, a Redbus-like system design, and HR discussions, and I was offered a job.
Full Experience
Hi everyone,
I recently participated in Rakuten's hiring drive and wanted to share my interview experience.
Round 1: Technical Round (Java & Spring Boot) - ~1 Hour
This round was entirely focused on Java and Spring Boot fundamentals.
Java: The interviewer asked in-depth questions about the JVM, Java memory management, Garbage Collection (GC) strategies, and concurrency. After that, we discussed the internal working of a HashMap (no implementation was required).
Spring Boot: We covered the differences between Spring and Spring Boot, Inversion of Control (IoC), Dependency Injection, and the different types of annotations used.
Overall, it was a straightforward discussion, and I would rate the difficulty as Easy.
Round 2: DSA, High-Level Design (HLD) & Puzzle - ~1 Hour
This round was a mix of coding, system design, and a logical puzzle.
DSA: I was asked to solve an easy LeetCode problem in Java: Rotate Array.
HLD: I was asked to design a system similar to Redbus. We had a thorough discussion on how to search for buses based on location and time. We also covered concurrency (e.g., handling scenarios where two users try to book the exact same seat simultaneously) and the design for the notification system. The interviewer seemed satisfied with my approach.
Puzzle: A standard puzzle: You have 2 candles, each of which burns in exactly 1 hour. How do you measure exactly 45 minutes?
This round went very well, and I would consider it Easy to Medium.
Round 3: Director/Managerial Round (In-Office) - 45 Minutes
This was an in-office round with the Director of the team. It felt more like a professional discussion than a traditional interview.
Project Discussion: We started with details about my current project and my responsibilities.
Architecture: I was asked how I would approach migrating a monolithic application to a microservices-based architecture.
Methodology: We discussed how Agile works in practice.
AI: The rest of the interview turned into an open discussion about AI. We talked about how I use AI in my day-to-day work, its limitations, its pros and cons, and whether it is useful in every scenario.
The HR reached out later and informed me that the feedback was positive.
Round 4: HR Round
This was a standard HR discussion covering salary expectations and other basic details.
Verdict: Selected!
I received an offer from Rakuten. However, I currently hold another offer and am still deciding which one to choose.
Good luck to everyone interviewing!
Interview Questions (3)
Rotate Array
Given an integer array nums and an integer k, rotate the array to the right by k steps, where k is non-negative.
Design Redbus-like Bus Booking System
Design a system similar to Redbus that allows users to search for buses based on location and time, handles concurrent seat bookings (e.g., two users attempting to book the same seat simultaneously), and includes a notification subsystem.
45-Minute Measurement Puzzle
Measure exactly 45 minutes using two candles that each burn for exactly 1 hour.