Data Engineer Interview Questions: Top 15 Questions & Sample Answers

by Hiration

Should you become a data engineer in 2022?

A study reveals that data engineering interviews have been growing at 40% year on year. This means that there are more data engineer positions available now than ever. So, it is a great time to be a data engineer!

Whether you are looking for a new role or breaking into a data engineering role, preparing for an upcoming data engineer interview can be overwhelming.

Although overwhelming, the data engineer interview preparation is important. The preparation can either ‘make it’ or ‘break it’ for you!

Also, given how competitive the job market is, you would not want to miss any base trying to land your dream job.

We have thus curated the top data engineer interview questions that you can likely expect during the interview.

Read on to prepare for your data engineer interview.

Basic Data Engineering Interview Questions


Here are some common data engineer interview questions that the recruiters often ask applicants during job application process:

Why Did You Choose Data Engineering as Your Career?


This could be one of the many first data engineer interview questions. This question judges your motivation, interest, and passion for data engineering. Employers wish to hire people who are enthusiastic about the role.

You might begin by telling your narrative and highlighting the aspects of data engineering that interest you the most. Share your story about how you started, what got you hooked on the job, how you upskilled yourself, and the difficulties you faced.

Why are you interested in this data engineering job? Why should we hire you?


It's a basic data engineer interview question, but your answer can set you apart from the competition.

Identify a few interesting elements about the role, or the kind of work the company is doing in that field that motivates you to join the company. Express why you adore the organization to indicate your interest in the position.

Link the following to the job and corporate culture in the second half of the question.

  • Abilities
  • Education
  • Personality
  • Professional experience

You can support your responses with examples from your past experience. Be careful to portray yourself as enthusiastic, confident, driven, and culturally suitable for the organization as you defend your suitability for the position and company.

What Are the Data Engineer Skills That You Possess?


If you want to be a decent data engineer, the skills required are:

  • Data modeling
  • Database design and database architecture
  • SQL and NoSQL
  • Data storage and distributed systems such as Hadoop (HDFS)
  • Data Visualization
  • Data warehousing and ETL (Extract Transform Load) tools
  • Strong computing and mathematical skills
  • Excellent communication, leadership, critical thinking, and problem-solving skills

Also Read: How to Draft a Data Engineer Resume?

What Is the Most Challenging Thing about Being a Data Engineer?


The employer understands that not every part of the job is easy. Be honest while answering this data engineer interview question. It is not intended to pinpoint weaknesses but to see how you work through things you find difficult.

Hiration pro tip:
Mention previous circumstances where you encountered a challenge and how you tackled it.

How Is the Job of a Data Engineer Different from That of a Data Architect?


This question is intended to see if you realize that there are distinctions in the data warehouse teams. Both of their roles overlap or differ based on the database maintenance department's or the company's demands. Hence, they work closely together, but there are differences in their general responsibilities.

Also Read: Data Engineer vs Data Scientist

Technical Data Engineering Interview Questions


Check out the following data engineering interview questions and sample answers:

What is Data Engineering?


This is a basic data engineering interview question. The interviewer wishes to understand your definition of data engineering and what the job entails.

Sample Answer: We live in an era of overabundant available data. The data requires cleaning and distilling for it to be useful. Data engineering entails aggregating huge sets of data and turning them into useful information to provide intelligence and carry out actionable strategies.

How Does a Data Warehouse Differ from an Operational Database?


Such data engineer questions may be intended for mid-level professionals, but they could be asked of entry-level candidates as well.

Sample Answer: The operational database provides real-time information on the operations of the day. A data warehouse keeps account of the historical data for the management and the executives to make informed decisions. For instance, an operational database would contain information on new customers that have signed up, log of complaints or orders placed on a day to day basis. But a data warehouse would contain information on the number of orders generated last month and this month which when compared gives insight into what is working for the business.

What Do *args and *kwargs Mean?


If you are interviewing for an advanced role, you should be able to answer complex data engineer questions on coding such as this.

Sample Answer: args defines an ordered function, and kwargs represents the unordered arguments used in a function.

Hiration pro tip:
Be prepared to write codes using *args and *kwargs function if asked by the interviewer.

Do You Have Any Experience with Data Modeling?


Such data engineer questions will certainly be asked during your interview if you are applying for a role that demands experience.

Begin with a simple yes or no response. Even if you don't have much expertise in data modeling, you should be able to define it. If you have prior experience, you can go into further depth about what you've done.

Sample Answer: Data modeling is a scientific method of documenting complicated data systems pictorially. The process of transforming and processing retrieved data and then sending it to the concerned individuals is also known as data modeling.
I have utilized software like Talend and Pentaho to model data.

Name the Essential Frameworks and Applications for Data Engineers?


Such interview questions for data engineer is frequently asked to judge if you have the necessary technical abilities. Mention the names of frameworks and your level of familiarity with each.

Mention frameworks such as Spark, Flink, Kafka, etc and applications such as SQL, Hadoop, Python. Also, mention the frameworks that you would wish to learn and why.

What Are the Big Data’s Four V’s?


Such interview questions for data engineer is frequently asked to test the technical capability of the interviewee.

Sample Answer:The Big Data’s four V’s are:
1. The velocity of Data: It is the rate at which Big Data is being generated over time.
2. Variety of Data: The various forms of Big Data such as images, log files, media files, and voice recordings.
3. The volume of Data: It could be the number of users, the size of data, the number of tables, etc.
4. The veracity of Data: It decides the uncertainty or certainty of the data.

Could You Explain the Different Types of Data Modeling Design Schemas?


Such interview questions for data engineer is frequently asked to determine if the candidate possesses the desired knowledge.

Sample Answer: There are primarily two types of schemas in data modeling:
1) Snowflake schema
2) Star schema

Hiration pro tip:
Expand on any or all of the points you've been asked to explain.

Take Us Through an Algorithm You Used in a Recent Project.


Such data engineer interview questions determine the suitability of the candidate.

You must choose an algorithm that you are knowledgeable about and that is preferably employed by the organization. There will be follow-up questions to gauge the depth of your response, such as,

  • What factors influenced your decision to use this algorithm?
  • Is this algorithm scalable?
  • What obstacles did you experience when utilizing this algorithm? How did you approach them?

What Is a Block and How Does a Block Scanner Work?


Such data engineer interview questions determine the technical acumen of the candidate.

Sample Answer: Blocks are the smallest unit of data allotted to a file, which the Hadoop system produces automatically for storage in distributed file systems on separate nodes. Block Scanner checks the data blocks stored on a DataNode to ensure its integrity.

What Is a Namenode and How Does a Namenode Crash Affect You?


Such data engineer interview questions determine the technical prowess of the interviewee.

Sample Answer: NameNodes keep the metadata of the files on the cluster. Essentially, metadata includes pieces of information such as block location, file size, and hierarchy. It's analogous to a File Allocation Table (FAT), which keeps track of the data blocks that make up files and where they're kept on a single machine. For a distributed file system, NameNodes store the same information.

Under typical conditions, a NameNode crash will result in data loss, even if all data blocks are intact. In a high-availability system, a passive NameNode backs up the primary one and takes over if the primary one fails.

Also read: Data Engineer’s Salary in 2022

Key Takeaways


Landing your dream job as a data engineer requires interview preparation.

  • Interview questions for data engineers can be divided into two parts: basic and technical
  • Basic data engineer questions test your motivation and passion behind pursuing the career
  • Technical data engineer questions require you to be skilled at the job and express the details to the interviewer
  • Prepare well for the interview to increase your chances of getting shortlisted

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