4500+ Senior Software Engineer Interview Questions and Answers

A controller is a component that handles incoming requests and returns a response, while a REST controller specifically handles RESTful requests.

• A controller is responsible for handling various types of requests, such as HTTP, WebSocket, etc.

• A REST controller is a type of controller that specifically handles RESTful requests, which follow the principles of Representational State Transfer (REST).

• REST controllers typically use annotations like @RestController and @RequestMappin...read more

DELETE removes specific rows from a table, while TRUNCATE removes all rows and resets auto-increment values.

• DELETE is a DML command, while TRUNCATE is a DDL command.

• DELETE can be rolled back, while TRUNCATE cannot be rolled back.

• DELETE triggers ON DELETE triggers, while TRUNCATE does not trigger any triggers.

• DELETE is slower as it logs individual row deletions, while TRUNCATE is faster as it logs the deallocation of data pages.

• Example: DELETE FROM table_name WHERE condition; ...read more

Java is platform independent because it compiles code into bytecode that can run on any system with a JVM, which is platform dependent.

• Java code is compiled into bytecode, which is platform independent

• The JVM interprets the bytecode and translates it into machine code specific to the underlying platform

• This allows Java programs to run on any system with a JVM installed, making Java platform independent

Snowflake offers virtual warehouses in various sizes for different computing needs.

• Sizes available for virtual warehouses in Snowflake include X-Small, Small, Medium, Large, X-Large, 2X-Large, and 4X-Large.

• The size utilized in the current project depends on the specific computing requirements and workload demands.

• For example, a Small virtual warehouse may be sufficient for basic data processing tasks, while a 4X-Large warehouse may be needed for complex analytics or large-sca...read more

Common testing questions related to Linux and operating systems

• What are the different types of testing that can be performed on a Linux operating system?

• How do you test the compatibility of software with different Linux distributions?

• Can you explain the process of testing kernel modules in a Linux environment?

• What tools and techniques do you use for performance testing on Linux systems?

• How do you ensure the security and stability of a Linux server through testing?

Modifying the POCO class allows extending the entity with additional properties.

• To add extra properties, simply modify the POCO class by adding new properties.

• Ensure that the changes are reflected in the database schema if necessary.

• Update any existing code that interacts with the POCO class to handle the new properties.

• Consider the impact on serialization, validation, and any other relevant aspects.

Use SQL GROUP BY and ORDER BY DESC to fetch the highest row of each group in a dataset.

• Use GROUP BY to aggregate data based on a specific column.

• Use ORDER BY DESC to sort the results in descending order.

• Use LIMIT 1 to fetch only the top result from each group.

• Example: SELECT department, MAX(salary) FROM employees GROUP BY department ORDER BY MAX(salary) DESC LIMIT 1;

• This query retrieves the department with the highest salary.

SOLID principles are a set of five design principles in object-oriented programming to make software designs more understandable, flexible, and maintainable.

• S - Single Responsibility Principle: A class should have only one reason to change.

• O - Open/Closed Principle: Software entities should be open for extension but closed for modification.

• L - Liskov Substitution Principle: Objects of a superclass should be replaceable with objects of its subclasses without affecting the func...read more

Delegates are reference types that hold a reference to a method. They are used to achieve loose coupling and event handling.

• Delegates allow methods to be passed as parameters to other methods.

• They can be used to define callback methods.

• Built-in delegates in C# include Action, Func, Predicate, EventHandler, and Comparison.

• Action and Func are used for methods that return void and non-void values respectively.

• Predicate is used for methods that return a Boolean value.

• EventHandler...read more

Parallel stream is not always beneficial in Java Stream API.

• Parallel stream can be slower than sequential stream for small data sets or when the overhead of parallelism is greater than the benefit.

• Parallel stream can be beneficial for large data sets or when the operations are independent and can be executed in parallel.

• It is important to measure the performance of both sequential and parallel streams for a specific use case to determine which is more efficient.

Autowiring in Spring Boot is a way to automatically inject dependencies into Spring beans.

• Autowiring is a feature in Spring that allows the container to automatically inject the dependencies of a bean.

• There are different modes of autowiring in Spring: 'byName', 'byType', 'constructor', 'autodetect', and 'no'.

• For example, in 'byName' autowiring, Spring looks for a bean with the same name as the property being autowired.

The starter dependency of the Spring Boot module is spring-boot-starter-parent.

• The starter dependency of Spring Boot provides a set of default configurations and dependencies to kickstart a Spring Boot project.

• It includes commonly used dependencies like spring-boot-starter-web, spring-boot-starter-data-jpa, etc.

• The spring-boot-starter-parent also manages the versions of all dependencies to ensure compatibility.

Answering questions related to creating GQL server, directives, fragments, unit tests, TypeScript features, and React.js functionalities.

• To create a GQL server, you can use tools like Apollo Server or Express with GraphQL middleware.

• Directives in GQL are used to modify the behavior of a field or fragment in a query. For example, @include and @skip are common directives.

• Fragments in GQL allow you to define reusable units of query logic. They can be included in queries to avoid...read more

I am highly proficient in HTML, CSS, and JavaScript.

• Extensive experience in building responsive web applications using HTML, CSS, and JavaScript

• Strong understanding of front-end frameworks like React, Angular, or Vue.js

• Familiarity with CSS preprocessors like SASS or LESS

• Knowledge of modern JavaScript ES6+ features and best practices

• Experience in optimizing web performance and cross-browser compatibility

Find the largest island area in a grid representing an ocean using DFS or BFS.

• Use Depth-First Search (DFS) or Breadth-First Search (BFS) to explore the grid.

• Mark visited cells to avoid counting them multiple times.

• Count the size of each island during the traversal.

• Example: For a grid [[1,0,0],[1,1,0],[0,0,1]], the largest island has area 3.

• Keep track of the maximum area found during the exploration.

Implement a function to ensure unique first names, last names, and photos for 10 consecutive button clicks.

• Use a set to store generated names and photos to ensure uniqueness.

• Create a loop that simulates clicking the button 10 times.

• Check if the generated name or photo already exists in the set.

• If a duplicate is found, regenerate until a unique one is obtained.

• Example: If 'John' is generated, check if 'John' is in the set before adding.

List is mutable and Tuple is immutable in Python.

• List can be modified after creation while Tuple cannot be modified.

• List uses square brackets [] while Tuple uses parentheses ().

• List is used for homogenous data while Tuple is used for heterogenous data.

• List is slower than Tuple in terms of performance.

• Example of List: [1, 2, 3] and Example of Tuple: (1, 'hello', 3.14)

let, var, and const are all used to declare variables in JavaScript, but they have different scoping rules and behaviors.

• let and const were introduced in ES6, while var has been around since the beginning of JavaScript.

• let and const are block-scoped, while var is function-scoped.

• Variables declared with const cannot be reassigned, while let and var can be.

• const variables must be initialized when they are declared, while let and var can be declared without initialization.

• Exampl...read more

Implement an API in Java to fetch top rated movies in a certain genre from an external datasource using pagination.

• Create a REST API endpoint in Java using Spring Boot framework

• Implement pagination by using query parameters for 'page' and 'size'

• Filter the movies by genre and sort them by rating to fetch the top rated ones

• Use a service layer to interact with the external datasource and fetch the data

• Return the filtered and paginated movie data in the response

To switch between tabs in a browser using Selenium, we can use the getWindowHandles() method and switchTo() method.

• Use getWindowHandles() method to get the handles of all open tabs

• Store the handles in a Set

• Use switchTo() method to switch to a specific tab by passing the handle as an argument

Spring Boot offers basic annotations like @SpringBootApplication, @RestController, @Autowired, @RequestMapping, @Component, @Service, @Repository.

• @SpringBootApplication - Used to mark the main class of a Spring Boot application.

• @RestController - Used to define a RESTful controller.

• @Autowired - Used for automatic dependency injection.

• @RequestMapping - Used to map web requests to specific handler methods.

• @Component - Used to indicate a class is a Spring component.

• @Service - Use...read more

The @SpringBootApplication annotation is used to mark the main class of a Spring Boot application.

• It is a combination of @Configuration, @EnableAutoConfiguration, and @ComponentScan annotations.

• It tells Spring Boot to start adding beans based on classpath settings, other beans, and various property settings.

• It is often placed on the main class that contains the main method to bootstrap the Spring Boot application.

To find code performance issues in production, use monitoring tools and profiling techniques.

• Use monitoring tools like New Relic, AppDynamics, or Datadog to track performance metrics and identify bottlenecks.

• Use profiling techniques like CPU profiling, memory profiling, and network profiling to pinpoint specific areas of the code that are causing performance issues.

• Analyze logs and error messages to identify patterns and potential performance issues.

• Perform load testing and s...read more

Yes, we can override or replace the embedded Tomcat server in Spring Boot.

• Spring Boot allows for customization of embedded servers through configuration properties.

• You can replace Tomcat with other embedded servers like Jetty or Undertow.

• Example: To use Jetty instead of Tomcat, exclude Tomcat dependencies and include Jetty dependencies in your pom.xml file.

Yes

• Use AJAX or WebSocket to send file data to the server

• Track the progress of the file upload using the 'progress' event

• Calculate the percentage of completion based on the total file size and the amount uploaded

Design a service to aggregate multiple sources of data/documentation centrally.

• Identify sources of data/documentation

• Determine data aggregation method

• Design a centralized database to store aggregated data

• Develop a user-friendly interface to access the data

• Ensure data security and privacy

The start() method is used to start a new thread and execute the run() method.

• The start() method creates a new thread and calls the run() method.

• The run() method contains the code that will be executed in the new thread.

• Calling the run() method directly will not create a new thread.

• The start() method should be called to start the execution of the new thread.