3500+ Senior Software Engineer Interview Questions and Answers

Distributed systems are a network of independent computers that work together to achieve a common goal. Security can be maintained through encryption, authentication, access control, and monitoring.

• Distributed systems consist of multiple computers that communicate and coordinate actions to achieve a common goal.

• Security in distributed systems can be maintained through encryption of data in transit and at rest.

• Authentication mechanisms such as passwords, tokens, or biometrics ...read more

Generator functions and symbols in JavaScript. Implementation of const keyword in ES5.

• Generator functions are functions that can be paused and resumed, allowing for lazy evaluation of data.

• Symbols are a new primitive type in ES6 that can be used as unique identifiers.

• To implement const in ES5, we can use Object.defineProperty to create a read-only property on an object.

Yes, I have worked on Kafka. My code had 10 partitions.

• Yes, I have experience working with Kafka and have implemented code with multiple partitions.

• In one of my projects, I used Kafka with 10 partitions to distribute the workload efficiently.

• Having multiple partitions in Kafka helped in achieving high throughput and scalability for real-time data processing.

Java 8 introduced several new features including lambda expressions, functional interfaces, streams, and default methods.

• Lambda expressions: Enable functional programming in Java by expressing instances of single-method interfaces (functional interfaces) concisely.

• Functional interfaces: Interfaces with a single abstract method, such as java.util.function.Function or java.util.function.Predicate.

• Streams: Allow for processing sequences of elements in a functional style, support...read more

Interfaces define contracts for behavior while abstract classes provide partial implementation.

• Interfaces cannot have implementation while abstract classes can have partial implementation.

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

• Interfaces are used for loose coupling while abstract classes are used for code reuse.

• Example: An interface 'Drawable' can define a method 'draw' which any class implementing it must define. An abstract cl...read more

An unique id for a massive parallel system can be generated using a combination of timestamp, machine id and a random number.

• Use a timestamp to ensure uniqueness

• Include a machine id to avoid collisions in a distributed system

• Add a random number to further increase uniqueness

• Consider using a UUID (Universally Unique Identifier) for simplicity

• Ensure the id generation algorithm is thread-safe

Thread Scheduler is responsible for managing the execution of multiple threads in a multitasking environment.

• Thread Scheduler determines the order in which threads are executed.

• It allocates CPU time to each thread based on priority and scheduling algorithm.

• Time Slicing is a technique used by Thread Scheduler to allocate a fixed time slice to each thread before switching to another.

• It ensures fair execution of threads and prevents a single thread from monopolizing the CPU.

• Exam...read more

package.json is a file that contains metadata about a project and its dependencies.

• package.json is used in Node.js projects to manage dependencies

• Dependencies are packages required for the project to run

• Dev dependencies are packages required for development and testing

• Dependencies and dev dependencies are listed separately in package.json

• Example: "dependencies": {"express": "^4.17.1"}, "devDependencies": {"nodemon": "^2.0.7"}

CTE, Temp table and Table variable are used to store temporary data in SQL Server.

• CTE (Common Table Expression) is a temporary named result set that can be referenced within a SELECT, INSERT, UPDATE, or DELETE statement.

• Temp table is a physical table that is created in the tempdb database and can be used to store temporary data.

• Table variable is a variable that can store a result set for later use and is similar to a temp table but is stored in memory.

• CTE is useful for recurs...read more

Yes, a new column can be added in between 2 existing columns in a table by altering the table structure.

• Yes, a new column can be added in between 2 existing columns by using the ALTER TABLE statement in SQL.

• The new column can be specified to be added after a specific existing column.

• For example, ALTER TABLE table_name ADD new_column_name datatype AFTER existing_column_name;

Interview questions for Senior Software Engineer position

• Array list vs linked list - array list is faster for random access, linked list is better for frequent insertions/deletions

• Getters and setters are used for encapsulation and to control access to class variables

• Loose coupling allows for easier maintenance and testing, tight coupling can lead to code that is difficult to modify

• Spring Boot is a framework for building standalone applications, MVC is a design pattern for sep...read more

Array is a fixed-size collection of elements, while stack is a data structure that follows Last In First Out (LIFO) principle.

• Array is a static data structure, while stack is a dynamic data structure.

• In array, elements are accessed using index, while in stack, elements are accessed using push and pop operations.

• Linked list is a data structure where each element points to the next element, types include singly linked list, doubly linked list, and circular linked list.

• Advantage...read more

I am highly skilled in automating infrastructure using scripting and coding.

• Proficient in scripting languages like Python, Bash, and PowerShell

• Experience in using configuration management tools like Ansible and Chef

• Familiarity with cloud platforms like AWS and Azure and their automation tools

• Implemented infrastructure as code using tools like Terraform

• Automated deployment pipelines using tools like Jenkins and GitLab CI/CD

• Examples: Wrote Python scripts to automate AWS EC2 ins...read more

API stands for Application Programming Interface. REST and SOAP are two types of APIs.

• REST is an architectural style that uses HTTP protocol for communication and supports multiple data formats like JSON, XML, etc.

• SOAP is a protocol that uses XML for communication and supports only XML data format.

• REST is lightweight and easy to use, while SOAP is more complex and requires more bandwidth.

• REST is stateless, while SOAP maintains state information.

• REST is widely used for web ser...read more

Event loop is a mechanism that allows for asynchronous execution of code by managing the order of events in a single thread.

• Event loop continuously checks the call stack for any functions that need to be executed, and processes them in a non-blocking manner.

• Different types of queues in event loop include microtask queue (Promise callbacks), macrotask queue (setTimeout, setInterval callbacks), and animation frame queue (requestAnimationFrame callbacks).

VPC stands for Virtual Private Cloud, which is a virtual network in the cloud.

• VPC allows users to create their own isolated network within the cloud

• It provides control over network topology, IP address range, and subnets

• VPC can be used to securely connect resources in the cloud and on-premises

• Examples of cloud providers that offer VPC are Amazon Web Services and Google Cloud Platform

Makemytrip blocks seat for 15 mins by using a hold on the seat inventory.

• Makemytrip uses a hold on the seat inventory to block the seat for 15 mins.

• If the payment doesn't go through, the hold is released and the seat becomes available again.

• This ensures that the seat is not booked by someone else during the payment process.

• The hold time can vary depending on the airline's policy.

• Makemytrip also sends reminders to complete the payment before the hold expires.

Indexes in SQL are data structures that improve the speed of data retrieval operations by allowing quick access to specific rows in a table.

• Indexes are used to quickly locate rows in a table without having to search the entire table.

• They are important because they can significantly improve the performance of SELECT queries by reducing the time taken to retrieve data.

• Indexes can be created on one or more columns in a table to speed up search operations.

• Examples of indexes incl...read more

RESTful services are web services that follow the REST architecture while WebAPI is a framework for building RESTful services.

• RESTful services use HTTP methods like GET, POST, PUT, DELETE to perform CRUD operations on resources

• WebAPI is a framework for building RESTful services using .NET framework

• WebAPI provides features like routing, model binding, content negotiation, etc.

• RESTful services can be consumed by any client that can make HTTP requests

• WebAPI can be used to build ...read more

ArrayList is implemented as a resizable array, while LinkedList is implemented as a doubly linked list.

• ArrayList provides fast random access and slower insertion/deletion, while LinkedList provides fast insertion/deletion and slower random access.

• ArrayList uses less memory overhead compared to LinkedList.

• Example: ArrayList is more suitable for scenarios where random access is frequent, while LinkedList is more suitable for scenarios where frequent insertion/deletion is requir...read more

INNER JOIN returns only the rows that have matching values in both tables, while LEFT JOIN returns all rows from the left table and the matched rows from the right table.

• INNER JOIN is used to retrieve rows from both tables that have matching values based on the specified condition.

• LEFT JOIN is used to retrieve all rows from the left table, along with the matched rows from the right table. If there is no match, NULL values are returned for the right table columns.

• Example: If w...read more

Use AWS Amplify to easily deploy static web applications from GitHub.

• Create an AWS Amplify app and connect it to your GitHub repository.

• Configure the build settings for your app in the Amplify console.

• Push changes to your GitHub repository and Amplify will automatically build and deploy your app.

• Customize your deployment settings and add features like authentication and analytics.

• Amplify supports a variety of static site generators and frameworks, including React, Vue, and An...read more

The finally block will always execute, even if an exception is thrown from the try block.

• The finally block is used to execute code that should always run, regardless of whether an exception is thrown or not.

• If an exception is thrown from the try block, the code in the finally block will still execute.

• This is useful for cleaning up resources, such as closing files or database connections.

• Example: try { // code that may throw an exception } finally { // code that should always ...read more

Types of Trigger in Oracle forms and their sequence of firing.

• Types of triggers include Key Triggers, Mouse Triggers, and Timer Triggers.

• Key Triggers fire when a key is pressed or released.

• Mouse Triggers fire when the mouse is clicked or moved.

• Timer Triggers fire at a specified interval.

• The sequence of trigger firing is Pre-Form, Pre-Block, Pre-Record, Post-Record, Post-Block, and Post-Form.

To scale a monolith architecture and improve response time, use horizontal scaling and implement caching.

• Implement horizontal scaling by adding more instances of the monolith application behind a load balancer

• Use a distributed cache to store frequently accessed data and reduce database queries

• Implement caching at different levels such as application-level caching, database query caching, and HTTP response caching

• Use a caching strategy based on the data access patterns and exp...read more

The design pattern is used to solve a specific problem in software development.

• Design patterns are reusable solutions to common problems in software development.

• They provide a standard way to solve a problem that can be adapted to different situations.

• Examples of design patterns include Singleton, Factory, Observer, and Decorator.

• Using design patterns can improve code quality, maintainability, and scalability.

Views in databases are virtual tables that display data from one or more tables based on a query.

• Views are used to simplify complex queries by storing them as a virtual table.

• They can hide the complexity of underlying tables and provide a layer of security by restricting access to certain columns.

• Types of views include simple views, complex views, materialized views, and indexed views.