800+ Java Interview Questions & Answers for 2 to 5 and 5 to 10+ years of experience & architects

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500+ Big Data Interview Questions & Answers for 2 to 5 and 5 to 10+ years of experience & architects

200+ Big Data Interview Q&As.

Big Data Engineer interview questions answered for 2 to 5 years of experience.

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06: Pyspark SCD Type 1 & Type 2 Interview Q&As with tutorials

This extends Pyspark with schema & a simple join of two data frames example.

Q13: What is SCD Type 1, and how will you implement it in pyspark?
A13: SCD stands for Slowly Changing Dimension, and it was explained in 10 Data warehouse interview Q&As.

In short, SCD Type 1 overwrites the changes against the existing data.… Read more ...



05: Pyspark read from a file & add new columns interview Q&As with tutorial

This extends Pyspark with schema & a simple join of two data frames example.

Q08: How would you read csv data into a spark Dataframe?
A08: Here is the tutorial step by step that reads employee.csv file into the Dataframe.

Step 1: Create a .csv file named employee.csv under a folder say /tmp.

Step 2: Write a pyspark job named read_csv_spark.pyRead more ...



04: Pyspark testing interview Q&As with pytest tutorial

This extends Pyspark testing interview Q&As with unittest tutorial.

Q04: How would you go about writing init tests to test your pyspark transformations and functions?
A04: Here is a complete example using a popular python third-party testing library pytest. The pytest is a robust testing framework for Python that makes it easy to write simple and scalable test cases.… Read more ...



03: Pyspark testing interview Q&As with unittest tutorial

This extends Pyspark with schema & a simple join of two data frames example.

Q01: Why should you test the pyspark pipelines?
A01: The data pipelines need to be tested as data pipelines evolve with new functionalities and enhancements to existing processes, tests provide the confidence that the new changes do not break the pipeline’s existing functionality. There are different types of tests like unit testing, integration testing & end-to-end testing.… Read more ...



02: Pyspark with schema & a simple join of two data frames example

This extends Installing & getting started with Pyspark on Mac tutorial, and assumes that pyspark has been properly set up. If you are using a Windows OS, please google for “installing pyspark on Windows” or “getting started with pyspark on windows”.

In the previous tutorial we have set up pyspark & ran a very simple job. In this tutorial, go up a notch to create dataframes with a schema & join two data frames & print the joined result.… Read more ...



01: Installing & getting started with Pyspark on Mac tutorial

This post shows how to get pyspark installed using the installer for Mac known as the homebrew. Homebrew is a package manager for MacOS (and Linux). It can be used to install, update, and manage various applications and tools on Macs. If you don’t have Homebrew, install it first as a pre-requisite.

Data Engineers with Python, SQL, Cloud (e.g. AWS, Azure), pyspark & Databricks are sought-after.… Read more ...



03: Shell script (i.e Bash) interview Q&As – function calls & return values

Q01 How does Bash functions accept input arguments?
A01 You can define a function that will accept parameters while calling the function. These parameters would be represented by $1, $2 and so on.

Q02 Can Bash functions return a value as an output?
A02 Even though a function has a return statement, it is used to return the exit code value, which is a numeric value that represents success or failure.… Read more ...



27: 50+ SQL scenarios based interview Q&As – identifying consecutive records

The data analysts & engineers will often be faced with the below SQL scenario at work. It is also often asked in job interviews. This solution uses SQL analytical functions & you can learn more about them at SQL analytic functions interview questions – Part 1

Setup the data on db-fiddle MySQL V8.0 to practice.

Q. Given the below input:

How will you write SQL query to output the count of consecutive statuses of jobs?… Read more ...



Java Developer & Architect Interview Q&As

Java & Big Data Tutorials

Prepare to fast-track & go places

FAQs are marked with 🔥 as some questions are not only more popular with the interviewers, but also required to build robust systems. If you are an interviewer, cover well rounded topics to judge real experience.

Don't be overwhelmed by the number of questions as the technology stacks are so vast. The quality of the answers you provide to some of the key technical & open-ended questions along with your soft skills & attitude will go a long way in getting the job offers.

Note: Some Q&As belong to more than one category.
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