20+ Zensar Technologies Software Developer Interview Questions and Answers

I am comfortable with multiple computer languages.

• Java

• Python

• C++

• JavaScript

Data marts are subsets of data warehouses that focus on specific business areas or departments.

• Types of data marts include dependent data marts, independent data marts, and hybrid data marts.

• Dependent data marts rely on the data warehouse for data, while independent data marts do not.

• Hybrid data marts combine elements of both dependent and independent data marts.

• Examples of data marts include sales data mart, marketing data mart, and finance data mart.

Fact Table contains quantitative data and measures, while Dimension Table contains descriptive attributes.

• Fact Table contains numerical data that can be aggregated (e.g. sales revenue, quantity sold)

• Dimension Table contains descriptive attributes for analysis (e.g. product name, customer details)

• Fact Table typically has a larger number of rows compared to Dimension Table

• Fact Table is usually normalized, while Dimension Table is denormalized for faster query performance

Outliers are data points that significantly differ from the rest of the data in a dataset.

• Outliers can skew statistical analysis and machine learning models.

• They can be caused by errors in data collection, measurement errors, or genuine anomalies.

• For example, in a dataset of employee salaries, a CEO's salary may be an outlier compared to the rest of the employees' salaries.

Deploying a Big Data model involves several key steps to ensure successful implementation.

• Prepare the data for deployment by cleaning and transforming it as needed.

• Choose the appropriate deployment environment, such as on-premises or cloud-based.

• Implement the model using a suitable technology stack, such as Hadoop or Spark.

• Test the deployed model to ensure accuracy and efficiency.

• Monitor the performance of the deployed model and make necessary adjustments.

• Scale the deployment...read more

ETL process involves extracting data from various sources, transforming it to fit the data warehouse schema, and loading it into the warehouse.

• Extract: Data is extracted from multiple sources such as databases, files, APIs, etc.

• Transform: Data is cleaned, filtered, aggregated, and transformed to match the data warehouse schema.

• Load: Transformed data is loaded into the data warehouse for analysis and reporting.

• Example: Extracting customer information from a CRM system, transfo...read more

Load testing in Tableau involves using tools like TabJolt or custom scripts to simulate user activity and measure performance.

• Use TabJolt, a free load testing tool provided by Tableau, to simulate user activity and measure performance.

• Create custom scripts using tools like JMeter or Selenium to simulate user interactions and test performance under different load conditions.

• Monitor server performance metrics during load testing to identify bottlenecks and optimize performance....read more

Power BI is a business analytics tool that provides interactive visualizations and business intelligence capabilities.

• Power BI allows users to connect to a wide variety of data sources and create interactive reports and dashboards.

• Users can easily share their insights with others by publishing their reports to the Power BI service.

• Power BI also offers AI capabilities for data analysis and visualization, such as natural language queries and image recognition.

• The comprehensive ...read more

Power BI is a Microsoft business analytics tool while Tableau is a data visualization tool with more advanced features.

• Power BI is more user-friendly and integrates well with other Microsoft products.

• Tableau has more advanced visualization capabilities and is preferred for complex data analysis.

• Power BI is better suited for organizations already using Microsoft products, while Tableau is more popular among data analysts and data scientists.

• Tableau has a steeper learning curve...read more

Different types of joins in Tableau include Inner Join, Left Join, Right Join, and Full Outer Join.

• Inner Join: Returns only the rows that have matching values in both tables.

• Left Join: Returns all rows from the left table and the matched rows from the right table.

• Right Join: Returns all rows from the right table and the matched rows from the left table.

• Full Outer Join: Returns all rows when there is a match in either left or right table.

Various types of filters in Tableau include extract filters, context filters, data source filters, and quick filters.

• Extract filters: Filters data directly from the extract before it is loaded into Tableau.

• Context filters: Filters data based on the order of operations in Tableau, allowing for more control over filtering.

• Data source filters: Filters data at the data source level before it is loaded into Tableau.

• Quick filters: Interactive filters that allow users to easily filt...read more

The building blocks of Power BI include datasets, reports, dashboards, and workspaces.

• Datasets - the foundation of Power BI, containing the raw data for analysis

• Reports - visual representations of data from datasets

• Dashboards - a collection of visuals from reports for monitoring key metrics

• Workspaces - collaborative environments for sharing and managing Power BI content

OLAP is used for analyzing historical data while OLTP is used for managing real-time transactional data.

• OLAP stands for Online Analytical Processing, used for data analysis and reporting.

• OLTP stands for Online Transaction Processing, used for managing real-time transactional data.

• OLAP is optimized for read-heavy workloads, while OLTP is optimized for write-heavy workloads.

• OLAP databases are typically denormalized for faster query performance, while OLTP databases are normaliz...read more

C++ is a compiled language while Java is an interpreted language.

• C++ is faster and more efficient than Java.

• Java is platform-independent while C++ is platform-dependent.

• C++ supports multiple inheritance while Java does not.

• Java has automatic garbage collection while C++ does not.

• C++ allows for low-level memory manipulation while Java does not.

Social websites like Twitter and Reddit can help improve verbal abilities through discussions and debates.

• Twitter allows users to engage in conversations and debates with people from all over the world.

• Reddit has various subreddits dedicated to discussions on different topics, which can help improve vocabulary and communication skills.

• Quora is another platform where users can ask and answer questions, which can help improve critical thinking and verbal abilities.

Volatile variables are used to indicate that a variable's value can be changed unexpectedly, while atomic variables ensure that operations on the variable are executed as a single, indivisible unit.

• Volatile variables are used when a variable's value can be changed by multiple threads or external factors, and the compiler should not optimize access to that variable.

• Atomic variables ensure that operations on the variable are executed atomically, meaning they are indivisible and...read more

The OSI model has 7 layers that define how data is transmitted over a network.

• The layers are: Physical, Data Link, Network, Transport, Session, Presentation, and Application.

• Each layer has a specific function and communicates with the layers above and below it.

• The Physical layer deals with the physical transmission of data, while the Application layer deals with user interfaces.

• Examples of protocols that operate at different layers include Ethernet at the Data Link layer and ...read more

String is immutable, String Buffer is mutable. OOPs concept focuses on objects and classes. Exception handling is used to handle runtime errors.

• String is immutable, meaning its value cannot be changed once it is created. String Buffer is mutable, allowing for modifications to the value.

• OOPs concept revolves around the idea of objects and classes, where objects are instances of classes and encapsulate data and behavior.

• Exception handling is used to handle runtime errors and pr...read more

Understanding SQL joins and types with code examples

• Types of SQL joins include INNER JOIN, LEFT JOIN, RIGHT JOIN, and FULL JOIN

• INNER JOIN returns rows when there is at least one match in both tables

• LEFT JOIN returns all rows from the left table and the matched rows from the right table

• RIGHT JOIN returns all rows from the right table and the matched rows from the left table

• FULL JOIN returns rows when there is a match in one of the tables

• Example: SELECT * FROM table1 INNER JOIN...read more

OOPS concepts are fundamental to software development. They include inheritance, encapsulation, abstraction, and polymorphism.

• Inheritance allows a class to inherit properties and methods from another class.

• Encapsulation is the practice of hiding data and methods within a class, so they cannot be accessed from outside the class.

• Abstraction is the process of simplifying complex systems by breaking them down into smaller, more manageable parts.

• Polymorphism allows objects to take...read more

Caching can be implemented by storing frequently accessed data in a temporary storage area to improve performance.

• Use caching libraries like Redis or Memcached to store data in memory for quick access

• Implement caching at different levels such as application-level caching, database query caching, and HTTP caching

• Set expiration times for cached data to ensure freshness and prevent stale data

• Use caching strategies like lazy loading, write-through, write-behind, and cache-aside t...read more