Preparing for Hadoop Interview

3 years ago only a small number of companies were using Hadoop. Now Hadoop technology has grown leaps and bounds so as its user base. Companies from virtually all domains have begun committing to Big Data technologies. Due to this fact, we notice a high surge in the volume of opportunities within the Big Data or Hadoop space. With this increase in demand for Hadoop professionals additionally we see Hadoop interviews maturing a good deal. We see numerous complex, scenario based, analytical questions asked in the interviews. It has become essential for any beginner or even an experienced Hadoop professional to be technically prepared before they show up to an interview.

Hadoop interviews vary from other technical interviews. When you are interviewing for a Java developer position you would run into numerous technical questions in Java and very little about the use case of your project and the infrastructure. In Hadoop interviews equal emphasis is given to the use case, infrastructure as well as the technical elements of the Hadoop related tools used by you.

The initial question you most likely hear in a Hadoop interview is to talk about how you used Hadoop in your recent project. How you answer this question explains significantly about your understanding of the Hadoop framework. Have good answers to explain why your client or company chose to use Hadoop to solve key issues or use cases. Offer a concrete use case and explain why it had been harder to solve the situation making use of traditional approach like RDBMS and explain how you solved the problem using Hadoop.

Be familiar with your cluster. Interviewers are incredibly intrigued to learn about your cluster and ways in which it was managed. You can expect to hear questions from cloud services like AWS and your expertise in it. It is a good idea to get ready for this question in advance. Make sure you be aware of number of nodes, data volume, replication factor, block size, number of mappers and reducers per node, memory allocated to the mappers and reducers, distribution used etc.

Next comes your role in the project. Question like – Did you involve in the initial design and sizing of your Hadoop cluster? This is a common question even if you’re not seeking an architect position. Then comes the list of Hadoop ecosystem tools you’re familiar with. At this point technical questions commences to trickle down. Scenario based questions are certainly common at this stage. Often questions are asked based on a scenario or problem that your interviewer faced in the past and will be interested to check out the way in which solve the problem.

Troubleshooting and optimizations questions are really common in Hadoop interviews. Most interviewees unfortunately fail at this point not because they are not really acquainted or worked on troubleshooting and optimizations related problem but because of their insufficient preparation in this particular topic. Take a look at the sample questions and answers from the Hadoop Developer Interview Guide to get an idea of the questions and answers asked in Hadoop Developer interviews.

From our experience when interviewees attempt to put together answers on the fly it never usually works out. Practise and preparing your responses ahead of time is essential.

Good Luck !!!