3500+ Senior Software Engineer Interview Questions and Answers

O-Auth is an open standard for authorization. Our project uses token-based authentication for security.

• O-Auth is used to allow users to grant access to their resources without sharing their credentials.

• It uses tokens for authentication instead of passwords.

• Our project uses token-based authentication for security purposes.

• Token-based authentication involves generating a unique token for each user that is used to authenticate their requests.

Find the max triplets such that i

• Sort the array in ascending order

• Iterate over the array and keep track of the maximum triplet

• Return the maximum triplet

Using Java 8 Streams to find and print the third highest employee in an employee list.

• Sort the employee list in descending order based on their salaries.

• Skip the first two employees to get the third highest employee.

• Print the details of the third highest employee.

SQL databases are relational databases that use structured query language, while NoSQL databases are non-relational databases that use various data models.

• SQL databases are based on a fixed schema, while NoSQL databases are schema-less.

• SQL databases are better suited for complex queries and structured data, while NoSQL databases are better for unstructured and semi-structured data.

• SQL databases ensure ACID (Atomicity, Consistency, Isolation, Durability) properties, while NoSQ...read more

Flask is lightweight and good for small projects, while Django is more robust and suitable for larger projects.

• Flask is good for small projects with simple requirements

• Django is more suitable for larger projects with complex requirements

• Flask is lightweight and flexible, allowing for more customization

• Django has a lot of built-in features and is more opinionated

• Flask is better for RESTful APIs and microservices

• Django is better for full-stack web applications

• Examples of Flask ...read more

Value types hold the data directly, while reference types hold a reference to the data.

• Value types are stored on the stack, while reference types are stored on the heap.

• String is a reference type in .NET.

• Value types include int, float, and bool.

• Reference types include arrays, classes, and interfaces.

Authentication was implemented using JWT tokens and OAuth 2.0. Tech stack includes Node.js, Express, MongoDB, and React.

• JWT tokens were used for user authentication and authorization.

• OAuth 2.0 was used for third-party authentication.

• Node.js and Express were used for the backend.

• MongoDB was used for the database.

• React was used for the frontend.

Watcher is used to monitor changes in variables during runtime, while breakpoint is used to pause program execution at a specific line of code.

• Watcher is used to track the value of a variable or expression during program execution.

• Breakpoint is used to pause the program at a specific line of code to allow for debugging.

• Watchers are typically set up in debugging tools like IDEs, while breakpoints are set by the developer in the code itself.

• Example: Setting a watcher on a varia...read more

A value converter in WPF is used to convert data from one type to another for binding purposes.

• Converts data between different types for data binding

• Implements the IValueConverter interface in WPF

• Can be used to format data for display in UI elements

• Example: converting a boolean value to a visibility enum for showing/hiding elements

Self Join is a way to join a table with itself using aliases.

• It is useful when we need to compare records within the same table.

• It requires the use of aliases to differentiate between the two instances of the same table.

• Example: SELECT a.name, b.name FROM employees a, employees b WHERE a.manager_id = b.employee_id;

Yes, I have experience implementing server driven UIs.

• Implemented server driven UIs using JSON responses to dynamically update UI elements

• Worked with frameworks like React and Angular to handle server driven UI updates

• Used server driven UIs to efficiently manage and display large amounts of data

Core Data is a framework provided by Apple for managing the model layer objects in an iOS application.

• Core Data is used for storing, retrieving, and managing data in an iOS app.

• It provides an object-oriented interface to work with data.

• Operations include creating, reading, updating, and deleting data.

• Example: Creating a new record in Core Data for a user profile.

• Example: Fetching a list of items from Core Data to display in a table view.

Program to change background color on button click in Angular

• Create a button in Angular template

• Add click event listener to the button

• Use setInterval() function to change background color after every 0.5 sec

• Use ngStyle directive to change background color dynamically

Partial is a method in MVC that renders a specific portion of a view, while render partial renders a partial view.

• Partial is used to render a specific portion of a view, while render partial is used to render a partial view.

• Partial is typically used within a view to render a reusable component, while render partial is used to render a separate partial view.

• Partial can be used with parameters to pass data to the partial view, while render partial can also specify a different l...read more

Count the number of repeated integers in an array

• Iterate through the array and use a hash table to keep track of the count of each number

• Return the count of numbers with a count greater than 1

A function pointer is a variable that stores the memory address of a function.

• Function pointers can be used to pass functions as arguments to other functions.

• Syntax: return_type (*pointer_name)(parameter_list);

• Example: int (*func_ptr)(int, int) = &add;

• Example: int result = (*func_ptr)(2, 3);

Before commit and After commit Microflows are used in Mendix to perform actions before and after committing changes to the database.

• Before commit Microflows are executed before the changes are committed to the database.

• They are used to perform validations, calculations, or any other actions that need to be done before saving the data.

• After commit Microflows are executed after the changes are committed to the database.

• They are used to perform additional actions, such as sendin...read more

Questions related to Java programming language and Spring framework

• Inheritance is a mechanism in Java where a class acquires the properties of another class

• Spring Boot is a popular framework for building web applications in Java

• Advantages of Spring Boot include easy configuration, auto-configuration, and embedded servers

• Spring annotations are used to provide metadata to the Spring framework

• Some common Spring annotations include @Autowired, @Controller, and @Service

• Design patt...read more

JIT compiles code at runtime while AOT compiles code during build time.

• JIT stands for Just-In-Time compilation and compiles code at runtime.

• AOT stands for Ahead-Of-Time compilation and compiles code during build time.

• JIT is used in development mode while AOT is used in production mode.

• JIT compiles templates and components on the fly while AOT compiles them before runtime.

• AOT generates smaller and faster code compared to JIT.

Multithreading is the execution of multiple threads of a single process, while multiprocessing is the execution of multiple processes.

• Multithreading involves multiple threads within a single process, while multiprocessing involves multiple processes.

• Multithreading shares the same memory space, while multiprocessing has separate memory spaces.

• Multithreading is suitable for I/O-bound tasks, while multiprocessing is suitable for CPU-bound tasks.

• Multithreading is more efficient i...read more

SQL Server Agent is a job scheduling tool in SQL Server. Abstract classes cannot be instantiated. SPs are faster than functions. Microservice concepts. IEnumerable vs IQueryable.

• SQL Server Agent is a job scheduling tool in SQL Server for automating tasks like backups, database maintenance, etc.

• Abstract classes cannot be instantiated because they are incomplete and meant to be extended by subclasses.

• Extension methods can be created for abstract classes to add new functionality...read more

Cache memory is used to store frequently accessed data for faster retrieval, improving application performance.

• Cache memory reduces the time taken to access data by storing frequently used data closer to the processor.

• It helps in improving the overall performance of the application by reducing latency.

• Different types of cache memory include L1, L2, and L3 caches, each with varying sizes and speeds.

• In my application, we used L1 cache for storing critical data that needed to be...read more

The question asks for programs on Java 8 and 11, multithreading, collections, design patterns, SOLID principles, Spring MVC and Boot, and REST API.

• Java 8 and 11 programs: Provide examples of programs written in Java 8 and 11.

• Multithreading: Discuss the concept of multithreading and provide examples of how it can be implemented in Java.

• Collections: Explain the different types of collections in Java and their usage.

• Design patterns: Discuss commonly used design patterns in softw...read more

Using Stream API to find odd numbers, square them, and calculate their sum.

• Use Stream API filter to find odd numbers

• Use map to square the odd numbers

• Use reduce to calculate the sum

Use command line tools like 'ps' or 'top' to find the number of running processes on a server.

• Use 'ps aux' command to list all running processes and count the number of lines

• Use 'top' command and look for the 'Tasks' section which shows the number of running processes

• Use 'htop' command which provides a more interactive and detailed view of running processes

GC stands for Garbage Collection. It is an automatic memory management process in programming languages.

• GC is responsible for reclaiming memory that is no longer in use by the program.

• It identifies and frees up memory occupied by objects that are no longer reachable.

• GC has different algorithms like Mark and Sweep, Copying, and Generational.

• The life cycle of an object involves creation, usage, and eventual garbage collection.

• GC can be triggered by various conditions like memor...read more

Create Linked List without using internal library and provide add, delete, find functionality.

• Create a Node class with data and next pointer

• Create a LinkedList class with head pointer and methods to add, delete, and find nodes

• Use a loop to traverse the list and perform operations

• Handle edge cases such as adding to an empty list or deleting the head node

SDLC and STLC, list vs tuple, assert vs verify

• SDLC (Software Development Life Cycle) is a process followed to develop software

• STLC (Software Testing Life Cycle) is a process followed to test software

• List and tuple are both data structures in Python, but list is mutable while tuple is immutable

• Assert is used to check if a condition is true, while verify is used to check if a web element is present

• Both assert and verify are used in automated testing

• Example: assert 2+2 == 4, ver...read more

To create a high performant event driver microservice, we need to focus on efficient event handling and scalability.

• Use asynchronous event-driven architecture

• Choose a lightweight and efficient framework like Node.js or Go

• Implement caching and load balancing techniques

• Optimize database queries and use NoSQL databases for faster data retrieval

• Use containerization and orchestration tools like Docker and Kubernetes for scalability

• Implement monitoring and logging to identify and r...read more

Migration scripts help in updating the database schema when changes are made to the code first model.

• Migration scripts are used to update the database schema to match the code first model

• They help in keeping the database schema in sync with the code first model

• They are executed automatically when the application starts or manually using the Package Manager Console

• They can be used to add, modify or delete database objects like tables, columns, indexes, etc.

• They can be versione...read more

T4 templates are used to generate code or text files based on a template and input data.

• T4 templates automate repetitive code generation tasks.

• They can be used to generate code for data access layers, service layers, or UI components.

• T4 templates can also be used to generate configuration files or documentation.

• They provide a way to separate the logic from the generated output.

• T4 templates support customizing the generated code based on input parameters or conditions.

Create a Login form with email validation using Vanilla JS.

• Create a form in HTML with input fields for email and password

• Use JavaScript to validate the email input using regular expressions

• Display error messages if the email input is not in the correct format

Program to find second largest number in an array and list using streams and traditional methods.

• Use streams to find second largest number in array: Arrays.stream(array).distinct().sorted().skip(array.length - 2).findFirst().orElse(null)

• Use traditional method to find second largest number in list: Sort the list in descending order and get the element at index 1

• Ensure to handle edge cases like empty array/list or arrays/lists with less than 2 elements

Yes, SQL Functions can be used on the JOIN Clause.

• SQL Functions can be used on the JOIN Clause to manipulate the data before joining.

• Examples of SQL Functions that can be used on the JOIN Clause are CONCAT, SUBSTRING, and DATE_FORMAT.

• Using SQL Functions on the JOIN Clause can improve query performance and reduce the amount of data transferred.

To find the second largest number in a column in MySQL, you can use the ORDER BY and LIMIT clauses.

• Write a SELECT statement to retrieve the column values in descending order using ORDER BY.

• Use the LIMIT clause to limit the result set to the second row.

• The value in the second row will be the second largest number in the column.

The number of max and min approvals required in a release pipeline depends on the organization's policies and the complexity of the release.

• The number of approvals required can vary depending on the stage of the pipeline.

• Some organizations may require multiple levels of approval for critical releases.

• The number of approvals can also depend on the size and complexity of the release.

• Automation can help streamline the approval process and reduce the number of required approvals.

Reverse a given string and find unique values in an array of strings.

• Use the reverse() method to reverse the given string.

• Use a Set to store unique values in the array.

• Loop through the array and add each element to the Set.

• Convert the Set back to an array to get the unique values.

Java 8 Garbage collector follows the algorithm called G1 (Garbage-First).

• G1 divides the heap into regions and collects garbage in small portions called 'garbage-first' regions.

• It uses multiple parallel threads for garbage collection.

• G1 aims to minimize pause times by dynamically adjusting the amount of garbage collected in each region.

• It uses a combination of young and old generation collection to achieve better performance.

• G1 also supports concurrent garbage collection, allo...read more

SOLID is a set of principles for object-oriented programming to make software more maintainable, scalable, and robust.

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

• O - Open-Closed Principle: A class should be open for extension but closed for modification.

• L - Liskov Substitution Principle: Subtypes should be substitutable for their base types.

• I - Interface Segregation Principle: A client should not be forced to depend on methods it does no...read more

HashMap is a data structure that stores key-value pairs and uses hashing to quickly retrieve values based on keys.

• HashMap internally uses an array of linked lists to store key-value pairs.

• When a key-value pair is added, the key is hashed to determine the index in the array where it will be stored.

• If multiple keys hash to the same index, a linked list is used to handle collisions.

• To retrieve a value, the key is hashed again to find the corresponding index and then the linked l...read more

List is mutable while tuple is immutable in Python.

• List can be modified while tuple cannot be modified.

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

• List is slower than tuple in terms of performance.

• List is used for dynamic data while tuple is used for static data.

Function app is a serverless compute service that enables you to run code on-demand without having to manage infrastructure.

• Function app is used to run code on-demand without managing infrastructure

• It is a serverless compute service

• It supports multiple languages and integrates with other Azure services

• Examples of Function app include Azure Functions and Logic Apps

Mendix uses a multi-model database called Mendix Data Hub.

• Mendix Data Hub is a unified data layer that integrates with various databases.

• It supports both SQL and NoSQL databases.

• Examples of databases that can be used with Mendix include MySQL, PostgreSQL, MongoDB, and Oracle.

• Mendix Data Hub provides a visual interface for managing data models and relationships.

• It allows developers to easily connect and interact with data from different sources.