OnlineSales.ai Interview Experience for Software Developer

I applied for OnlineSales.ai through Campus.

The very first round was an online coding round where we were given some logs we have to write a code that can sort the logs according to their timestamp. We have to complete the task within 45 minutes.

I used Python for writing the code. After submitting my solution, on the same day, I received a mail that I have been selected for the next face-to-face rounds.

The face-to-face rounds conducted were:

First Round – Coding Round:

Stocks related problem statement was given where we have to return should we buy, sell or hold the stocks on the i’th day. 

Second Round:

Tell me about the code and the approach you used. How can the code be more optimized and what more things can be done alternatively in the code? Then we have to think of an approach to design and build a phone book how can the CRUD operations be performed in this phonebook?

Third Round:

Given a problem statement: there is an Amazon sale going on currently so, different discounts have to be given to the customers. There are three criteria 1. Customers can be prime or non-prime members. 2. Customer is frequent or not. 3. The mode of payment. 
We have to make combinations from these criteria and give discounts to the customers with matching the particular criteria combination. 
So, for different combinations of the criteria, there will be different discounts. Which data structure will you choose? What approach will you take? Basically, they were checking logical thinking. 

Fourth Round (Bar Raiser Round):

1. Design a DBMS for bank management where you have to store all transactions for banks all over India the DBMS should be connected to APIs and all. It should follow ACID properties, Normal forms, etc. 
2.  Write a code for limiting the number of API calls for each user. Each user can access an API 50 times per minute. After each minute the count gets reset to 50. If it is zero and the user calls the API again you have to handle it. 

Lastly some questions about yourself, your projects, the company and why do you want to join this company and they also checked my knowledge about web development.

After two days, I received a mail about being selected for OnlineSales.ai as a software developer.