100+ Software Engineer2 Interview Questions and Answers

SQL query to get the second highest salary in a table

• Use the MAX() function to find the highest salary

• Use the WHERE clause to exclude the highest salary

• Order the salaries in descending order and limit the result to 1

Improving problem complexity involves optimizing algorithms, reducing time/space usage, and leveraging data structures effectively.

• Analyze the algorithm's time complexity; for example, switching from O(n^2) to O(n log n) using a more efficient sorting algorithm.

• Utilize appropriate data structures; for instance, using a hash table for O(1) average time complexity in lookups instead of O(n) with arrays.

• Implement memoization or dynamic programming to avoid redundant calculations...read more

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

• Abstract class can have constructors, fields, and methods, while interface can only have constants and method signatures.

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

• Abstract classes are used to define a common behavior for subclasses, while interfaces are used to define a contract for classes to implement.

• Example: Abstract class ...read more

Standard ADSO is for persistent storage and reporting, while write optimized DSO is for temporary storage. Keys in ADSO are used for data modeling and performance optimization.

• Standard ADSO is used for persistent storage and reporting, while write optimized DSO is used for temporary storage before loading data to a standard ADSO.

• Write optimized DSO does not store data persistently, making it suitable for temporary data storage during data loads.

• Keys in ADSO are defined to uni...read more

Designing a database for an e-learning platform to manage user login and lecture content effectively.

• User Table: Stores user information like user_id, name, email, password_hash.

• Course Table: Contains course details such as course_id, title, description, and instructor_id.

• Lecture Table: Links to courses with fields like lecture_id, course_id, title, content, and duration.

• Enrollment Table: Manages user enrollments with user_id, course_id, enrollment_date.

• Progress Table: Tracks...read more

A comprehensive system flow for a pizza shop from order placement to delivery.

• Customer places an order via phone, website, or app.

• Order details are captured: type of pizza, size, toppings, and delivery address.

• Payment is processed through secure methods (credit card, PayPal, etc.).

• Order is sent to the kitchen for preparation.

• Pizza is prepared, baked, and packaged for delivery.

• Delivery driver is assigned and picks up the order.

• Driver delivers the pizza to the customer’s addres...read more

String manipulation using loops and conditionals for software engineering

• Use loops to iterate through each character in the string

• Use conditional statements to check for specific conditions and manipulate the string accordingly

• Examples: reversing a string, counting occurrences of a specific character, removing whitespace

Sharding the database is based on factors like scalability, performance, and data distribution.

• Consider sharding when the database is growing rapidly and needs to handle increased load.

• Shard based on geographical location to reduce latency for users in different regions.

• Shard based on specific data types or access patterns to optimize performance.

• Consider sharding when the database becomes too large to efficiently handle queries and transactions.

• Evaluate the trade-offs betwee...read more

The number of ways to reach the rightmost cell from the topmost cell in a 2D matrix can be calculated using dynamic programming.

• Use dynamic programming to calculate the number of ways to reach each cell in the matrix.

• At each cell, the number of ways to reach it is the sum of the number of ways to reach the cell above it and the cell to the left of it.

• The value in the rightmost cell will give the total number of ways to reach it from the topmost cell.

var, let, and const are all used for variable declaration in JavaScript, but they have different scopes and mutability.

• var is function-scoped and can be redeclared and reassigned

• let is block-scoped and can be reassigned but not redeclared

• const is block-scoped and cannot be reassigned or redeclared

Paytm uses microservices architecture for scalability and flexibility in system design.

• Paytm's system design is based on microservices architecture to break down the application into smaller, independent services.

• Each service in Paytm's architecture handles a specific function, such as payments, wallet, or shopping.

• Microservices communicate with each other through APIs, allowing for easier scalability and maintenance.

• This architecture enables Paytm to quickly add new features...read more

Design a microservices architecture to solve a specific problem, ensuring scalability, maintainability, and independent deployment.

• Service Decomposition: Break down the application into smaller, independent services, such as user management, payment processing, and inventory management.

• API Gateway: Implement an API gateway to handle requests, route them to appropriate services, and manage cross-cutting concerns like authentication and logging.

• Database per Service: Each micros...read more

Check if rectangles overlap by comparing their coordinates

• Compare the x and y coordinates of the two rectangles to see if they overlap

• If one rectangle is to the left of the other, or above the other, they do not overlap

• If the rectangles overlap, the x and y ranges will intersect

Designing an e2e payment system with detailed component explanation

• 1. Define user roles and permissions (e.g. customer, merchant, admin)

• 2. Implement secure payment gateway integration (e.g. Stripe, PayPal)

• 3. Develop user-friendly interfaces for payment processing

• 4. Ensure data encryption and compliance with PCI DSS standards

• 5. Set up automated payment notifications and transaction tracking

Design APIs for user generated content to allow users to create, read, update, and delete their own content.

• Create API endpoint for users to create new content

• Read API endpoint to retrieve user's content

• Update API endpoint to allow users to modify their content

• Delete API endpoint to enable users to remove their content

Design a lending application with a robust database schema for managing loans, users, and transactions.

• Entities: Users, Loans, Payments, and Loan Types.

• Users table: user_id, name, email, phone, address.

• Loans table: loan_id, user_id, amount, interest_rate, start_date, end_date, status.

• Payments table: payment_id, loan_id, payment_date, amount, payment_method.

• Loan Types table: type_id, type_name, max_amount, min_amount, interest_rate.

Count nodes in a BST that fall within a specified range efficiently using recursion.

• A Binary Search Tree (BST) has the property that left children are less than the parent and right children are greater.

• To count nodes within a range [low, high], traverse the tree recursively.

• If the current node's value is less than low, recurse right; if greater than high, recurse left.

• If the current node's value is within the range, count it and recurse both left and right.

• Example: For a BST...read more

DNS (Domain Name System) is a system that translates domain names to IP addresses. UTS (User Thread Scheduler) architecture manages user-level threads.

• DNS is used to translate human-readable domain names (like www.example.com) to IP addresses (like 192.0.2.1).

• DNS operates through a distributed database system that stores domain name records.

• UTS architecture manages user-level threads in a multi-threaded environment, allowing for efficient scheduling and execution.

• UTS architec...read more

SQL query to fetch progress for given user id and course id

• Use SELECT statement to retrieve progress data

• Filter results using WHERE clause with user id and course id

• Join tables if progress data is stored in a separate table

Fixing rendering issues in a React project often involves debugging component states and props.

• Check component state: Ensure that the state is being updated correctly using setState or useState.

• Verify props: Make sure that the props being passed to components are correct and not undefined.

• Use React DevTools: Inspect the component tree to see if components are rendering as expected.

• Check for conditional rendering: Ensure that any conditions for rendering components are being m...read more

Design a low-level system for a shopping cart feature in Flipkart, focusing on components and interactions.

• User can add, remove, or update items in the cart.

• Each cart item includes product ID, quantity, and price.

• Cart should support multiple users with unique sessions.

• Implement a persistence layer to save cart state (e.g., Redis, database).

• Consider handling promotions and discounts on cart items.

• Provide an API for frontend to interact with the cart (e.g., RESTful services).

• En...read more

Determine the order of alphabets based on a list of words sorted in a custom way.

• Compare adjacent words to identify the first differing character.

• The first differing character determines the order of those two letters.

• Example: Given words ['abc', 'abf'], 'c' comes before 'f'.

• Continue this process for all pairs of adjacent words.

• Construct a directed graph to represent the order of characters.

I handle pressure by prioritizing tasks, staying organized, seeking support when needed, and practicing stress-relief techniques.

• Prioritize tasks based on deadlines and importance

• Stay organized with to-do lists and calendars

• Seek support from colleagues or supervisors when feeling overwhelmed

• Practice stress-relief techniques such as deep breathing or exercise

• Maintain a positive attitude and focus on problem-solving

To delete a node in a linked list with a given pointer, update the node's value and next pointer to the next node's value and next pointer.

• Set the value of the node to the value of the next node

• Set the next pointer of the node to the next node's next pointer

Designing a database for a ticket booking system involves managing users, events, bookings, and payments efficiently.

• Users table: Stores user information (e.g., user_id, name, email).

• Events table: Contains event details (e.g., event_id, title, date, venue).

• Bookings table: Links users to events (e.g., booking_id, user_id, event_id, seats_booked).

• Payments table: Records payment transactions (e.g., payment_id, booking_id, amount, payment_status).

• Venues table: Details about event...read more

Writing code on notepad instead of an IDE

• Ensure proper indentation and formatting

• Use comments to explain code

• Compile and test code manually

• Save frequently to avoid losing work

Yes, I enjoy solving puzzles as it challenges my problem-solving skills.

• I enjoy the mental challenge of puzzles

• It helps me improve my problem-solving skills

• Examples: Sudoku, crosswords, logic puzzles