Increff Interview Experience for Data Engineer 2022

I am a fourth-year Chemical engineering student at Jadavpur University. Increff came to my College around the second week of September 2022 with 3 roles :

• Backend Engineer
• Data Engineer
• QA Engineer

I opted for the data engineer role because I had done an internship as a data engineer. There were 4 rounds, first was a cognitive/behavioral assessment followed by an online assessment including aptitude, coding, and SQL. Finally, there were 2 technical interview rounds.

Rounds 1 & 2

The Behavioural round is also a screening round, so do answer consciously. The OA for all roles was a little different, especially in the difference of level between DSA problems and a number of SQL questions. One opting for the DE role can expect one or more SQL problems as compared to the backend or QA role. The OA comprised MCQs related to OOPs, OS, and DBMS. There were coding questions, both were easy to medium level. I solved one and could only partially solve the other. While I don’t remember the exact problems, they could be solved with Arrays and HashMaps. There were 3 (or 4) SQL problems all directly taken from Hackerrank. They didn’t require any use of CTE or window functions and were pretty basic. If you have a good grasp on joining and applying group-by, you should be good. However, I do recommend studying window functions as a lot of popular interview questions are based on them. The MCQs were moderate. You can prepare for those using GFG or InterviewBit. 

After OA, the shortlist for the interview was announced. There were 2 interviews.

Technical Interview 1

This was more broader and general. After some discussion on the projects I had worked on and previous internships, he started with the below questions.

Questions asked : 

•  Write the code for creating a linked list and explain the differences between a linked list and an array. (This was asked after he told me to choose a data structure and I went for Linked List)
• Minimum steps to measure 4 L in a jar using 2 jars of capacities 5 L and 3 L with no measurement calibrations. 
•  You are given 2 arrays you have to choose 1 element from each array and find the absolute difference between them. You have to find pair with the minimum absolute difference and return their absolute difference.

You can find the solution here: https://www.geeksforgeeks.org/smallest-difference-pair-values-two-unsorted-arrays/

All this had to be solved on a word document shared by them. The interview lasted for around 45 minutes.  After this, I was shortlisted for the second interview.

Technical Interview 2

This round was conducted approximately an hour after the first interview. It was with a senior developer in the company. He was very chill, and we had over a 30-minute discussion on SQL and some DBMS concepts. 

Questions asked : 

1. Create a database design for a shoe-selling company. This was followed up with many questions like
   1. Which column to make a Primary Key 
   2. If the table is normalized or not
   3. What changes to make to find some metrics
   4. Which column to index, followed by the different types of indexing like clustered and non clustered
   5. Some discussion on B and B+ Trees.
   6. Wildcards used in SQL
2.  Count Zeroes in a sorted binary matrix 
3.  A number of ways to make a sum of Rs 117 using denominations of Rs 1, 10, and 50.

After this, we had some discussion on the company, the tech stack used, and the type of work I might expect. 

Later that day, 4 people were selected 3 for the backend and one for the data Engineer. 

Verdict: Selected.