3500+ Senior Software Engineer Interview Questions and Answers

Abstract class and Interface are both used for abstraction, but with some differences.

• Abstract class can have both abstract and non-abstract methods, while Interface can only have abstract methods.

• A class can implement multiple interfaces, but can only inherit from one abstract class.

• Abstract class can have instance variables, while Interface cannot.

• Abstract class provides partial implementation, while Interface provides full abstraction.

• Example of using Abstract class: Creat...read more

Microflows and nanoflows are both used in Mendix for defining business logic, but they differ in their scope and complexity.

• Microflows are used for larger and more complex processes, while nanoflows are used for smaller and simpler processes.

• Microflows can have multiple activities and can be triggered by events, while nanoflows have a single activity and are typically called from microflows.

• Microflows can have input and output parameters, while nanoflows do not support parame...read more

Tech stack for designing a scalable Uber-like service.

• Use microservices architecture for scalability and fault tolerance.

• Choose a cloud provider with auto-scaling capabilities.

• Use a load balancer to distribute traffic across multiple instances.

• Use a NoSQL database for high availability and scalability.

• Use message queues for asynchronous communication between services.

• Use containerization for easy deployment and management.

• Use caching to improve performance.

• Use monitoring and ...read more

The question asks about using .every() and .includes() methods to check if each character of a string is present in another string.

• Loop through each element of the string

• Split the string into an array to access each character

• Use .every() method to check if each character is present in the user string

• Use .includes() method to check if the character is present

Program to find the longest palindrome substring in a given string.

• Iterate through the string and check for palindromes of different lengths

• Store the longest palindrome found

• Return the length and substring

Implemented JWT and OAuth authentication in Angular and .NET Core apps.

• Used Angular's HttpInterceptor to add JWT token to requests

• Implemented OAuth2 authentication using IdentityServer4 in .NET Core

• Stored user credentials securely using ASP.NET Core Identity

• Used HTTPS to encrypt data in transit

• Implemented role-based authorization using ASP.NET Core Identity

Custom hooks in React are reusable functions that allow you to extract component logic into separate functions for better code organization and reusability.

• Custom hooks are created using the 'use' prefix and can be used to share logic between components.

• Use cases for custom hooks include fetching data from an API, handling form state, managing local storage, and more.

• Example of a custom hook for API call: const useFetchData = (url) => { // logic to fetch data from API }

Node.js is a server-side JavaScript runtime environment.

• Node.js is built on top of the V8 JavaScript engine from Google Chrome.

• It allows developers to write server-side code in JavaScript.

• Node.js has a non-blocking I/O model, making it efficient for handling large amounts of data.

• Node.js has a vast library of modules available through npm (Node Package Manager).

Print pairs of adjacent elements in an array

• Loop through the array and print each pair of adjacent elements

• Use a for loop and access the elements using their indices

• Example: for i in 0 until a.length-1 print (a[i], a[i+1])

Integration, middleware, and EAI systems are technologies that enable communication and data exchange between different software applications.

• Integration involves connecting different software applications to enable data exchange and communication.

• Middleware is software that sits between different applications and facilitates communication and data exchange.

• EAI (Enterprise Application Integration) systems are a type of middleware that enable communication between different en...read more

Unix related questions for Senior Software Engineer interview

• A hard link is a direct link to the physical file on disk, while a symbolic link is a reference to the file by name.

• To find out the system's IP address in Unix, you can use commands like ifconfig or ip addr show.

• The chmod command in Unix is used to change the permissions of a file or directory.

• grep is used for searching text using regular expressions, while egrep is an extended version of grep with more powerful pat...read more

The biggest challenge in developing Azure solution was managing the complexity of the cloud environment.

• Managing the complexity of the cloud environment

• Ensuring scalability and reliability

• Integrating with existing systems

• Securing the solution

• Optimizing cost

• Example: Migrating a legacy application to Azure

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.

The color applied will be based on the specificity of the selector, with ID having higher specificity than class.

• ID has higher specificity than class in CSS

• Color applied will be based on the selector with higher specificity

• Example: If ID selector has color red and class selector has color blue, the color applied will be red

The code will throw an error because 'a' is declared but not initialized.

• The code will result in a ReferenceError because 'a' is declared but not assigned a value.

• Variables declared with 'const' must be initialized at the time of declaration.

• Initializing 'a' with a value before calling test() will prevent the error.

There are three types of variables in Java: local, instance, and static.

• Local variables are declared within a method or block and have limited scope.

• Instance variables are declared within a class but outside of any method and are accessible to all methods of the class.

• Static variables are declared with the static keyword and are shared among all instances of the class.

• Examples: int x; //instance variable, static int y; //static variable, void method() { int z; //local variabl...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.

Program to find last non-repeating character in a given string using Java 8 functions only.

• Use Java 8 Streams and Lambda's to filter the string and find the last non-repeating character.

• Create a Map to store the frequency of each character in the string.

• Use the filter() method to get the non-repeating characters and find the last one using reduce().

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

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

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

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

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)

The program prints a star pattern using asterisks and spaces.

• Use nested loops to iterate through rows and columns.

• Determine the number of asterisks and spaces to print in each row.

• Use conditional statements to decide when to print an asterisk or a space.

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

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

• 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.