Data Engineer Interview Experience ZS Associates | Crack Top Companies

In this blog, I am sharing my data engineer interview experience with ZS Associates in detail (interview rounds and questions asked).

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The recruitment process was as follows:

Round 1: Preliminary Round (Screening Round): Telephonic Round by HR

This round consisted of a detailed discussion about my college projects, including work I did on Databricks, Spark, Hadoop, and research projects like a web crawler that I developed during my studies.

The telephonic round lasted about 15 minutes and also included a question about why I wanted to work for ZS Associates.

Round 2: Technical Interview 1 (Operating System, SQL, DSA Round): 1 hour

I received a call from HR informing me that I had cleared the screening round and was shortlisted for the technical discussion. This round lasted about an hour and was conducted by a Consultant from ZS Associates.I got a call from HR that my screening round is cleared and I was shortlisted for technical discussion. This round lasted for about 1 hour and was taken by the Consultant of Zs Associates.

He gave me DSA questions.Solve the Fibonacci series problem using either a brute force approach or an optimized method. Explain your solution clearly and provide code examples where applicable.

Some questions on SQL & Databases

–Different types of joins

–Normalization concepts

–Database transaction concepts

–Explain the CAP theorem

–Difference between views vs tables

–Snowflake schema vs star schema

–Super key vs composite key

–Data warehouse vs database

He asked me to write SQL query to delete the duplicates from the table without using a distinct

Next, he started asking questions on Hadoop & Spark concepts:

–Explain the architecture of Hadoop & Spark.

–High availability in Hadoop & role of YARN.

–Spark SQL functions.

–Difference between narrow & wider transformations in Spark.

–How YARN works & NameNode.

–Difference between RDD, DataFrame & Dataset in Spark.

–How Hadoop stores the data using block size.

Finally, he asked me some questions on operating system and networking concepts:

–Virtual memory and its purpose.

–How the TCP protocol works.

–Differences between IPv4 and IPv6 addresses.

–The meaning and usage of semaphores in OS.

–Differences between stack and queue data structures.

–Synchronization in OS.

–What a deadlock is and the necessary conditions for it to occur.

–Differences between HTTP and HTTPS protocols.

–How RAM functions.

These topics are commonly covered when applying for a Data Engineer Intern role. Since freshers typically lack deep knowledge of data engineering concepts, questions are often framed around these fundamental areas.

Round 3: Technical Interview 2(Case Study Round): 1 hour

I received a call from HR informing me that my first round was cleared, and I was shortlisted for the technical discussion. This round lasted about 1 hour. HR provided a case study along with materials to prepare.

What the Case Study Round Entails:

You’ll need to demonstrate problem-solving skills, SQL query-writing abilities, technical knowledge, and analytical aptitude. The solution has to be submitted to HR within 30 minutes for evaluation.

How I Approached It: I developed solutions using SQL, flowcharts, algorithms, and data interpretation. Afterward, I sent my answers to HR via email for further discussion.

Tips to solve the case study:

–Clarify: Understand the problem thoroughly.

–Structure: Plan your approach logically.

–Analyze: Focus on relevant data and insights.

–Identify Opportunities: Pinpoint key areas to improve or optimize.

For the example to understand case study you can refer here to get an idea of the types of questions typically asked in the Data Engineer case study round.

Round 4: Technical Interview 2 (Case Study Discussion, Guesstimate & Technical Round): 1:30 minutes

This round focused on the solutions I submitted for the case study round. It started with my explanation of the Web Crawler project I worked on during college. I discussed how I designed the web crawler and used scraping techniques to extract website data.

The interviewer then reviewed my approach to the case study solution:

> He asked me to explain the logic of the SQL query that I wrote in the case study.

> He also questioned my data interpretation, asking why I assigned a ‘D’ value instead of ‘Y,’ assessing my data interpretation and problem-solving skills.

> Next, he asked me to share my screen and explain the flowchart, asking me to design it using Edraw.io.

> He then asked why I used the window function to solve the query and requested an alternative method to solve it. I used a join operation to get the same result.

The interviewer also asked some basic SQL questions:

– SQL Query: Write a query to find the third-highest salary in the employee table using the window function.

– RANK vs. DENSE_RANK: Explain the difference between these functions.

– WHERE vs. HAVING Clause: Discuss the difference between these clauses.

The round concluded with guesstimate questions:

-> Light Bulb Problem: A closed room contains three light bulbs, with three switches located outside the room. You may manipulate the switches before entering the room, but you can open the door only once. Identify which switch corresponds to each bulb.

-> Wire Burning Problem: Measure exactly 45 minutes using two identical wires, each taking 1 hour to burn. Note: The wires burn non-uniformly.

Round 5: Techno-Managerial Interview (Behavioral & Technical Round): 45 mins

This interview was conducted by the Principal Hiring Manager of ZS Associates. It lasted for about 45 minutes. I was asked to introduce myself, along with my college projects and achievements. He asked me some questions about Python, including which language I preferred to use as a data engineer. I mentioned Python. He also asked me some questions on Spark architecture, as I was interviewing for a data engineer intern role.

He then asked me what I knew about ZS Associates and why I wanted to join ZS.

He explained the working of their team, the tools and technologies used, and then asked how soon I could join for the internship. The conversation progressed smoothly as I responded to each question.

He asked me some questions about what I know about Zs Associates. Why ZS?

Round 6: HR Round (General Discussion & Offer): 15 mins

This round lasted about 15 minutes. I was asked about my college grades, skills, and projects. The talent team then explained the role, the type of work I could expect, the internship duration, and the potential for a full-time offer.

Later that day, I received positive feedback from HR and was excited to learn that I was selected for the Data Engineer Intern position at ZS Associates.

Finally, I was part of ZS Associates as Data Engineer Intern to start my career in data engineering. 😊

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