300+ Interview Questions and Answers

This JSON contains answers to interview questions for a Software Engineer position.

• Aggregation and composition are both forms of association in object-oriented programming.

• Aggregation represents a 'has-a' relationship, where one object contains another object as a part.

• Composition is a stronger form of aggregation, where the lifetime of the contained object is controlled by the container object.

• Fibonacci series can be printed using recursion by defining a recursive function t...read more

Emergency change is raised to resolve an incident while urgent change needs top level approvals to proceed.

• Emergency change is not a part of the normal change process and does not have a lead time.

• ECAB needs to be arranged for emergency change.

• Urgent change needs to be implemented on an urgent basis and cannot wait to follow the entire change process.

• Top level approvals are required for urgent change to proceed.

A PIR is conducted to understand the reason and root cause of the failure and to document and update it.

• Conduct a PIR to understand the reason and root cause of the failure

• Document and update the PIR

• Identify what could be done differently next time to avoid such a situation

To improve performance of a Spring Boot application, consider optimizing database queries, caching, using asynchronous processing, and monitoring performance metrics.

• Optimize database queries by using indexes, avoiding N+1 queries, and limiting the amount of data fetched.

• Implement caching to store frequently accessed data in memory, reducing the need to fetch data from the database repeatedly.

• Use asynchronous processing for time-consuming tasks to free up resources and improv...read more

Implemented logging in Spring Boot application using SLF4J and Logback

• Added dependencies for SLF4J and Logback in pom.xml

• Configured logback.xml for logging levels and appenders

• Injected Logger instances using @Autowired annotation in classes

• Used logger.debug(), logger.info(), logger.error() methods for logging

Creating immutable class of orders, sorting orders, finding average of lists of integers.

• Create an immutable class Orders with private final fields and no setter methods.

• Override equals() and hashCode() methods to ensure uniqueness of objects.

• Use Collections.unmodifiableSet() to create a set of orders and Collections.sort() to sort them.

• Iterate through the List of List of String of integers, convert to integers, and calculate average for each list.

The time taken for the clock to tick from 8'o clock to 11'o clock is 105 seconds.

• Each tick represents 1/8th of an hour (45 minutes) on the clock.

• From 8'o clock to 11'o clock, there are 3 hours, so the total time taken is 3 * 45 = 135 minutes = 135 * 60 = 8100 seconds.

• The time taken for the clock to tick from 8'o clock to 11'o clock is 8100 - 35 = 8065 seconds.

Code to find number of occurrences of a word in a string

• Split the string into an array of words

• Loop through the array and count the occurrences of the given word

Pass by reference and pass by value are two ways of passing arguments to a function.

• Pass by value means a copy of the argument is passed to the function

• Pass by reference means the memory address of the argument is passed to the function

• Pass by value is used for primitive data types like int, float, etc.

• Pass by reference is used for complex data types like arrays, objects, etc.

To prevent Singleton from being broken by cloning, we can override the clone method and throw an exception.

• Override the clone method in the Singleton class and throw an exception to prevent cloning.

• Alternatively, you can return the same instance in the clone method instead of creating a new instance.

• Use serialization and deserialization to create a new instance of the Singleton class.

Yes, a callback function is a function that is passed as an argument to another function.

• Callback functions are commonly used in event handling, asynchronous programming, and functional programming.

• Example: setTimeout(function() { console.log('Hello!'); }, 1000);

• Example: array.map(function(item) { return item * 2; });

Initial SQL is a feature in Tableau that allows users to write custom SQL queries to connect to data sources.

• Initial SQL is used to execute SQL statements before the main query is executed.

• Custom SQL can be written in Tableau to connect to data sources that do not have a built-in connector.

• CAT in SQL stands for Concatenate and is used to combine two or more strings into a single string.

• Project related questions may vary depending on the specific project and requirements.

HDFS is the storage unit in Hadoop, providing fault-tolerant and scalable storage for big data.

• HDFS divides data into blocks and stores them across multiple machines in a cluster.

• It replicates data for fault tolerance, with default replication factor of 3.

• HDFS supports streaming data access and is optimized for large sequential reads.

• It provides high throughput and reliability for big data processing.

• HDFS is suitable for storing and processing large datasets in parallel.

Microservices are connected in REST APIs using communication protocols like HTTP, messaging queues, and service discovery.

• Microservices communicate with each other using HTTP requests and responses.

• Messaging queues like RabbitMQ or Kafka can be used for asynchronous communication between microservices.

• Service discovery tools like Eureka or Consul help in locating and connecting to different microservices.

• API Gateway can be used to aggregate multiple microservices into a singl...read more

Yes, DevOps is a set of practices that combines software development and IT operations to deliver high-quality software faster.

• DevOps is a culture and set of practices that emphasizes collaboration, automation, and monitoring throughout the software development lifecycle.

• It involves integrating development, testing, deployment, and operations teams to streamline the software delivery process.

• By using DevOps, database architects can ensure faster and more reliable delivery of ...read more

OOP concept focuses on creating objects that interact with each other. Interface is a contract for classes to implement, while abstract class can have some implemented methods.

• OOP concept involves creating objects that have properties and methods to interact with each other

• Interface is a contract that defines a set of methods that a class must implement

• Abstract class can have some implemented methods along with abstract methods that must be implemented by subclasses

HTML and CSS are used to create web pages.

• Start with creating the basic structure of the page using HTML tags.

• Use CSS to style the page and make it visually appealing.

• Add content to the page using HTML tags.

• Use CSS to position and layout the content on the page.

• Test the page in different browsers to ensure compatibility.

The number of times a for loop is used in a program varies depending on the program's requirements.

• The number of for loops used in a program depends on the program's logic and requirements.

• For loops are used to iterate over arrays, lists, and other data structures.

• Nested for loops are used to iterate over multi-dimensional arrays.

• For loops can also be used for counting and other repetitive tasks.

• The number of for loops used in a program can range from zero to many.

Use SQL queries with ORDER BY and LIMIT to find nth and 3rd highest record.

• Use ORDER BY column_name DESC to sort records in descending order

• Use LIMIT 1 OFFSET n-1 to get the nth highest record

• For 3rd highest record, use LIMIT 1 OFFSET 2