Lumiq Data Engineer Interview Questions and Answers

Round duration - 60 minutes
Round difficulty - Easy

Technical Interview round with questions on CSS and Jquery mainly.

Q1. What is the CSS box model?
Ans. 
The CSS box model is a design and layout concept that defines the structure and sizing of elements on a web page.
• It consists of content, padding, border, and margin around an element.

• Content area is where text and images are displayed.

• Padding is the space between the content and the border.

• Border is the line that goes around the padding and content.

• Margin is the space outside the border.

• Example: div { width: 200px; pad...read more
Answered by AI
Add your answer
Q2. How do you select all div elements using jQuery?
Ans. 
To select all div elements using jQuery, use the selector $('div').
• Use the jQuery selector $('div') to select all div elements on the page.

• You can also use the find() method to select div elements within a specific parent element.

• To perform actions on the selected div elements, use jQuery methods like css(), text(), or addClass().
Answered by AI
Add your answer
Q3. How can you change the background color of all items in JavaScript?
Ans. 
You can change the background color of all items in JavaScript by selecting all elements and setting their background color property.
• Select all elements using document.querySelectorAll()

• Loop through the selected elements and set their style.backgroundColor property

• Example: document.querySelectorAll('.item').forEach(item => item.style.backgroundColor = 'blue');
Answered by AI
Add your answer

Round duration - 60 minutes
Round difficulty - Easy

Technical Interview round with questions on Java mainly.

Q1. What are the uses of the final keyword in Java?
Ans. 
The final keyword in Java is used to define constants, prevent method overriding, and make a class immutable.
• Final variables cannot be reassigned once initialized

• Final methods cannot be overridden in subclasses

• Final classes cannot be extended
Answered by AI
Add your answer
Q2. What is the Front Controller in Spring MVC?
Ans. 
Front Controller in Spring MVC is a design pattern that handles all requests and acts as a central point of control.
• Front Controller is a servlet in Spring MVC that receives all requests and then dispatches them to the appropriate handlers.

• It helps in centralizing request handling logic, improving code organization and reducing duplication.

• Front Controller can perform tasks like authentication, logging, exception handl...read more
Answered by AI
Add your answer
Q3. What is the annotation for request mapping in Java?
Ans. 
The annotation for request mapping in Java is @RequestMapping.
• @RequestMapping annotation is used to map web requests to specific handler methods in Spring MVC.

• It can be applied at class level or method level to specify the URL path that the controller will handle.

• You can also specify HTTP request methods, headers, parameters, and more using @RequestMapping.
Answered by AI
Add your answer
Q4. What is the annotation used for a controller in Java?
Ans. 
The annotation used for a controller in Java is @RestController.
• Used to define a class as a controller in Spring MVC

• Automatically serializes return objects into JSON/XML responses

• Equivalent to @Controller + @ResponseBody annotations
Answered by AI
Add your answer

Round duration - 30 minutes
Round difficulty - Easy

This was a typical HR round.

Q1. NLP based question
Add your answer

Q1. Components of Databricks
Ans. 
Databricks is a unified data analytics platform that includes components like Databricks Workspace, Databricks Runtime, and Databricks Delta.
• Databricks Workspace: Collaborative environment for data science and engineering teams.

• Databricks Runtime: Optimized Apache Spark cluster for data processing.

• Databricks Delta: Unified data management system for data lakes.
Answered by AI
Add your answer
Q2. How to read a json file
Ans. 
To read a JSON file, use a programming language's built-in functions or libraries to parse the file and extract the data.
• Use a programming language like Python, Java, or JavaScript to read the JSON file.

• Import libraries like json in Python or json-simple in Java to parse the JSON data.

• Use functions like json.load() in Python to load the JSON file and convert it into a dictionary or object.

• Access the data in the JSON fi...read more
Answered by AI
Add your answer
Q3. Second highest salary SQL
Ans. 
To find the second highest salary in SQL, use the MAX function with a subquery or the LIMIT clause.
• Use the MAX function with a subquery to find the highest salary first, then use a WHERE clause to exclude it and find the second highest salary.

• Alternatively, use the LIMIT clause to select the second highest salary directly.

• Make sure to handle cases where there may be ties for the highest salary.
Answered by AI
Add your answer
Q4. How to configure the spark while creating the cluster
Ans. 
Spark cluster configuration involves setting up memory, cores, and other parameters for optimal performance.
• Specify the number of executors and executor memory

• Set the number of cores per executor

• Adjust the driver memory based on the application requirements

• Configure shuffle partitions for efficient data processing

• Enable dynamic allocation for better resource utilization
Answered by AI
Add your answer

Q1. Spark and airflow related questions
Add your answer
Q2. AWS services and it's related questions
Add your answer

Q1. Copy activity in ADF
Add your answer
Q2. Delta table, unity catalog , delta live table in Azure databricks
Add your answer

Q1. Copy activity, Lookup, get metadata, if else, for each activity in ADF
Add your answer
Q2. Conceptual ETL Questions like coalesce and repartition, cache, persist etc.
Add your answer