Round1

Leetcode
https://leetcode.com/problems/online-election/description/

What are the partitions in Kafka ?
What is Replication in Kafka?
What is Event driven architecture ?
What are different Isolation levels
Question on SpringBoot ?

SQL
Consider a scenario where you have a relational database schema for an e-commerce platform with three main tables: products, orders, and users. The products table contains information about various products available on the platform, the orders table tracks details of customer orders, and the users table stores user information.

Given this schema, please write a SQL query to retrieve the total number of orders placed by users who have made purchases of products within a specific category. Assume that the products table has the following columns: product_id, product_name, category_id, and the orders table has columns: order_id, user_id, product_id, order_date. You're asked to optimize this query for performance by utilizing composite indexes.
Could you Please provide the SQL query and explain your choices for composite indexes based on the query's filtering conditions and join operations.

Verdict: Strong Hire I was able to answer all the above question and solved the problem as well as sql query.
Round 2

Design a Restaurant Booking System
Design patterns
Spring starter dependencies

Verdict: Strong Hire I did the design and also incorporated extensions as well, at the end interviwer had some followup questions regarding the design, I answered them as well. He was very happy with the design I gave.

Round 3
Design a cart for an ecommerce application

We have an Ecommerce System where we have different services built already, your task is to build an InventoryOrchestratorService which will be responsible to save the cart state basis on different events happening in the system

CartService - managing the lifecycle of the cart

Orchestrator Service can use the following already builtin service

InventoryService - check the availability of the inventory
PricingService - check the pricing and taxes
DiscountingService - calculated discounted prices
DeliveryService - check deliverability and calculate delivery charges

This was a hiring manager round, he asked me for a LLD, I did based on what I could collect, then he added few questions about how would I make this deisgn extensible and then resiliant etc.
I explained about locking mechanisms.

The Interviewer was quiet the whole time, If I asked any question then he would reply after 40-50 secs. The expectation was not clear, Whatever I said in the interview he said "Yes Yes that's fine".

Got the rejection after few days, I aksed for a detailed feedback but they didn't share.