Direction Software LLP Software Engineer Interview Questions and Answers

Key features of Java 8 include lambda expressions, functional interfaces, streams, and default methods.

• Lambda expressions allow for functional programming style in Java.

• Functional interfaces enable the use of lambda expressions.

• Streams provide a way to work with collections in a more functional way.

• Default methods allow interfaces to have method implementations.

Yes, microservices can contain transactional data.

• Microservices can handle transactional data by using distributed transactions or event sourcing.

• Each microservice can manage its own database, which can include transactional data.

• Microservices can communicate with each other to ensure consistency in transactional data.

• Examples: E-commerce platform with separate microservices for inventory, orders, payments, etc.

Microservices can be updated with new data by using versioning, rolling updates, blue-green deployments, and canary releases.

• Use versioning to manage different versions of microservices.

• Implement rolling updates to gradually update instances without downtime.

• Utilize blue-green deployments to switch between old and new versions seamlessly.

• Employ canary releases to test new data on a small subset of users before full dep...read more

Technologies like Kafka, RabbitMQ, and Apache Pulsar can be used to update microservices with data.

• Kafka

• RabbitMQ

• Apache Pulsar

To configure login in Spring Boot, you can use Spring Security to handle authentication and authorization.

• Add Spring Security dependency in your pom.xml file

• Create a class that extends WebSecurityConfigurerAdapter to configure security settings

• Override configure(HttpSecurity http) method to define login form, login processing URL, success and failure URLs

• Use @EnableWebSecurity annotation on your main application class ...read more

Yes, I typically use a hash set or dictionary to filter out duplicate employee records from a list.

• Iterate through the list of employee records

• Use a hash set or dictionary to keep track of unique employee IDs

• Check each employee record against the hash set or dictionary to filter out duplicates

To identify an object in a collection, you can iterate through the collection and compare each object with the target object.

• Iterate through the collection using a loop

• Compare each object in the collection with the target object using a conditional statement

• Use a unique identifier or property of the object to match it with the target object

• Example: Identifying a specific student in a list of students by comparing their...read more

Implementing an authentication service involves creating a secure system for verifying user identities.

• Use encryption to securely store user passwords

• Implement multi-factor authentication for added security

• Utilize tokens or cookies for session management

• Integrate with OAuth or OpenID Connect for third-party authentication

• Implement rate limiting and account lockout mechanisms to prevent brute force attacks

REST services return data in JSON or XML format.

• Data is typically returned in JSON or XML format.

• JSON is more commonly used due to its simplicity and readability.

• REST services can also return data in other formats like HTML or plain text.

• Example: {"name": "John Doe", "age": 30}

Spring Boot actuator provides production-ready features to help monitor and manage your application.

• Provides endpoints to monitor application health, metrics, info, etc.

• Can be used to check the status of the application, database connections, and more.

• Allows customization and security configurations for the endpoints.

Securing a Spring Boot application, especially in the context of a banking application, involves implementing Spring Security.

• Use Spring Security to handle authentication and authorization

• Implement secure communication using HTTPS

• Utilize role-based access control to restrict user permissions

• Enable CSRF protection to prevent cross-site request forgery attacks

• Implement secure password storage and session management

Integrating Spring Data JPA with Spring Boot allows for easy database operations in a Spring Boot application.

• Add Spring Data JPA dependency in pom.xml

• Create JPA entity classes annotated with @Entity

• Create a repository interface extending JpaRepository

• Use repository interface in service classes for database operations

• Configure application.properties with database connection details

Yes, I have experience with job scheduling in previous projects.

• Utilized cron jobs to automate tasks at specific times

• Worked with tools like Apache Airflow for complex job scheduling workflows

• Implemented job scheduling in Python scripts using libraries like schedule or APScheduler

I used AngularJS and Bootstrap to create the UI side of the springboard application.

• AngularJS

• Bootstrap

Vaadin is an open-source web application framework for building modern web apps using Java.

• Vaadin allows developers to build web applications using Java on the server-side and HTML/CSS/JavaScript on the client-side.

• It provides a set of customizable UI components and a Java API for creating interactive web interfaces.

• Vaadin simplifies the development process by handling client-server communication and UI updates automat...read more

Fail-fast stops immediately upon detecting an error, while fail-safe continues to operate despite errors. Fail-safe is synchronized.

• Fail-fast immediately stops the operation upon encountering an error, ensuring that no further damage is done.

• Fail-safe continues to operate despite errors, often by handling the error and allowing the program to continue running.

• Fail-safe is synchronized, meaning that it is designed to ha...read more

Load factor in HashMap determines when the HashMap should be resized to maintain performance.

• Load factor is a measure of how full the HashMap is allowed to get before its capacity is automatically increased.

• The default load factor of HashMap is 0.75, which means the HashMap will be resized when it is 75% full.

• Increasing the load factor reduces the space overhead but increases the time cost of resolving collisions.

• Examp...read more

Multithreading in Java allows multiple threads to execute concurrently, improving performance and responsiveness.

• Multithreading allows multiple threads to run concurrently within a single process.

• Each thread has its own stack and program counter, but share the same heap memory.

• Java provides built-in support for multithreading through the java.lang.Thread class.

• Example: Creating a new thread by extending the Thread clas...read more

One-to-many and many-to-one relationships in Hibernate are used to define the relationship between entities in a database.

• One-to-many relationship: One entity can be associated with multiple instances of another entity. For example, one department can have multiple employees.

• Many-to-one relationship: Multiple instances of one entity can be associated with a single instance of another entity. For example, multiple emplo...read more

An ID in Hibernate is a unique identifier for an entity in a database. It is used to uniquely identify each record.

• ID is a field in an entity class annotated with @Id in Hibernate.

• It can be of different types like int, long, String, etc.

• ID is used to uniquely identify each record in a database table.

• It is often generated automatically using strategies like @GeneratedValue.

• Example: @Id @GeneratedValue(strategy = Generat...read more

DispatcherServlet is the front controller in Spring Boot that receives incoming requests and dispatches them to the appropriate handler.

• DispatcherServlet is a servlet that manages the flow of incoming requests in a Spring Boot application.

• It acts as the front controller, receiving all requests and then dispatching them to the appropriate handler for processing.

• DispatcherServlet is configured in the web.xml file or thro...read more

Communication between microservices can happen through synchronous or asynchronous protocols like HTTP, messaging queues, or gRPC.

• Microservices can communicate through synchronous protocols like HTTP, where one service sends a request to another service and waits for a response.

• Alternatively, microservices can communicate asynchronously using messaging queues like RabbitMQ or Kafka, where messages are sent between serv...read more

Messaging between microservices involves communication through message brokers or direct API calls.

• Microservices communicate through message brokers like RabbitMQ or Kafka.

• Messages are sent in a format like JSON or XML.

• Microservices can also communicate through direct API calls using REST or gRPC.

• Message queues help in decoupling services and ensuring reliable communication.

• Service discovery mechanisms like Consul or E...read more

Find max and min sum after removing one element from array. Time complexity analysis required.

• Iterate through array to find sum of all elements

• For each element, calculate sum after removing it

• Track max and min sum as you iterate

• Time complexity: O(n) where n is the number of elements in the array