Recuiter reached out to me on Linkedin for SDE III role in Walmart Sams Club.

Online Assessment (If Applicable)

Format

• Number of Questions: 2(1st is a Medium DSA question, 2nd is a Backend Repository Question)
• Duration: 60 min
• Difficulty: Medium

Result

• Cleared

Interview Process Overview

All the interview were Face-to-Face in Walmart Office on the same day.

Round 1 - DSA and Coding

All the questions were made to solve on whiteboard and the interview was focused on more discussion.

Questions

Question 1

Problem:

• binary-tree-level-order-traversal

Difficulty:
Medium

Approach Discussed:

• BFS Approach using queue

Follow-Ups:

• binary-tree-zigzag-level-order-traversal

Question 2

Problem:

• merge-intervals

Difficulty:
Medium

Follow-Ups:

• suppose now we have stream of intervals, how will you make sure that we get the correct overlapped intervals (got confused it with Median of Stream but interviewer said to think any other approach)

Round 2 - Low Level Design (LLD)

Interviewer asked me to open IDE of your choice and connect it with the screen.

Problem Statement

• Design Splitwise

Requirements Gathered

• The system should allow users to create accounts and manage their profile information.
• Users should be able to create groups and add other users to the groups.
• Users should be able to add expenses within a group, specifying the amount, description, and participants.
• The system should automatically split the expenses among the participants based on their share.
• Users should be able to view their individual balances with other users and settle up the balances.
• The system should support different split methods, such as equal split, percentage split, and exact amounts, but for interview create only Equal Split.

Classes Designed

User
Split
Group
Expense
BalanceSheet
SplitWise Service

Design Patterns Used

• Took Split as Abstract Class as each type has its own parameters
• Strategy for Different Split types

Discussion Points

• Interviewer was very helpful, he helped in every step and we discussed on every entity that we created.
• He was not looking for a working code but implementation of classes, Interfaces and services should be present. I coded 70% of the problem , Splitwise Service was remaining.

Feedback

• Positive Feedback and Good discussion
• Should focus more on Service Completion

Round 3 - High Level Design / System Design

This was supposed to be HLD Round, but the interview said we will do a LLD problem , it time permits then we can do HLD also for the same.

Problem

• Design Job Scheduler

Requirements

Functional Requirements

A scheduler should support:

• Submit jobs/tasks
• Execute jobs at scheduled time
• Support:
  • one-time jobs
  • recurring jobs
• Track job status
• Retry failed jobs
• Cancel jobs
• Multiple worker threads
• Priority handling (optional)

Classes Designed

Task
Job
Job Scheduler
Worker

Design Patterns Used

• Used PriorityBlocking Queue because we need to execute the high priority jobs earlier.
• Used ExecutorService for submitting jobs in queue
• Workers are using retrying mechanism of Exponential Backoff with Jitter

Discussion Points

• Interviewer was very helpful, we discussed on each entity and what kind of queue will be using, why not Delayed Queue or normal queue.
• He was not looking for a working code but small snippets of how would you implement these.

Feedback

• Positive Feedback

Managerial / Hiring Manager Round

In short, this round never happened 😔
After Third Round, this round was to be scheduled but HM wasn't available.
So HR told me HM round will happen virtually later.
Week Later called HR again for the feedback and HM round, Feedback is positive from all the 3 rounds, but hiring is Freezed under this HM.

Hence, Interview never Happened.

Result

Gave 3 round of interview for a Freezed role.

Thanks for reading. Feel free to ask any questions in the comments and I'll try to answer them.