100+ Software Engineer2 Interview Questions and Answers

Answering technical questions for Software Engineer 2 position

• To determine if a point is inside or outside a 2-manifold, use the ray casting algorithm

• To merge closeby points, use clustering algorithms like k-means or DBSCAN

• To determine if the normals of two triangles are wrongly oriented, use the cross product of their edges

• Favorite research paper and why

Design an Order and Cart Page in iOS with limit of 1 item per order.

• Create classes for Order, Cart, Item

• Implement network requests to fetch item details

• Use APIs to add item to cart and place order

• Design information flow from selecting item to placing order

To process large amount of data, use tools like Apache Hadoop, Apache Spark, or Google BigQuery.

• Utilize distributed computing frameworks like Apache Hadoop or Apache Spark for parallel processing of data

• Consider using cloud-based solutions like Google BigQuery for scalability and cost-effectiveness

• Optimize data processing pipelines by using tools like Apache Kafka for real-time data streaming

• Implement data compression techniques to reduce storage and processing overhead

The system design for the checkout feature on Amazon involves request body, API calls, load balancing, database caching, and CDN considerations.

• Request body includes user's selected items, shipping address, payment details, etc.

• API calls are made to process payment, update inventory, and send confirmation emails.

• Load balancing ensures even distribution of traffic across multiple servers to handle checkout requests efficiently.

• Database caching helps in storing frequently acces...read more

To find duplicates in an array of strings in linear time

• Create a hash table to store the frequency of each string

• Iterate through the array and check if the frequency of any string is greater than 1

• If yes, then it is a duplicate

• Return true if duplicates are found, else false

Abstract class allows partial implementation while interface allows full abstraction.

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

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

• Abstract class is used when some common functionality needs to be shared among subclasses, while interface is used to define a contract for classes to implement.

• Example: Abstract class 'Shape' with abst...read more

TDD stands for Test-Driven Development and BDD stands for Behavior-Driven Development. TDD focuses on writing tests before writing code, while BDD focuses on the behavior of the system.

• TDD involves writing a failing test, writing code to make the test pass, and then refactoring the code.

• BDD focuses on defining the behavior of the system through examples written in a specific format like Given-When-Then.

• TDD is more developer-centric, while BDD involves collaboration between de...read more

Optimise frequently searched items list by implementing caching, indexing, and prioritising popular items.

• Implement caching to store frequently searched items in memory for quick access.

• Use indexing to efficiently search and retrieve items from the list.

• Prioritise popular items by tracking search frequency and displaying them prominently.

• Consider implementing autocomplete or predictive search to suggest items as users type.

• Regularly update the list based on search trends to e...read more

I would assess the impact of the upgrade, plan the process, communicate with the customer, and ensure a smooth transition.

• Assess the current version of MySQL and the customer's requirements for the upgrade

• Plan the upgrade process including backups, testing, and rollback procedures

• Communicate with the customer about the timeline, potential downtime, and any impact on their system

• Ensure a smooth transition by monitoring the upgrade process and addressing any issues promptly

Creating custom hook, explaining virtual DOM, sorting an array in React

• To create a custom hook in React, you can define a function that starts with 'use' and can be reused across components.

• React's virtual DOM is a lightweight copy of the actual DOM, which allows React to efficiently update the real DOM.

• To sort an array in JavaScript, you can use the built-in 'sort' method or write a custom sorting function.

React is a JavaScript library for building user interfaces, while Angular is a full-fledged framework for building web applications.

• React is a library, while Angular is a framework

• React uses a virtual DOM for performance optimization, while Angular uses two-way data binding

• React components are simpler and more flexible, while Angular components are more opinionated and structured

• Angular has a built-in dependency injection system, while React relies on external libraries for s...read more

Generate string permutations with first letter as vowel and atleast 3 letters

• Create a list of vowels and a list of consonants

• Generate all possible permutations of length 3 or more using itertools.permutations

• Filter out permutations that do not start with a vowel

• Join the remaining permutations into strings

Process large amount of logs by using log aggregation tools like ELK stack or Splunk.

• Utilize log aggregation tools like ELK stack (Elasticsearch, Logstash, Kibana) or Splunk to collect, index, search, and visualize logs.

• Implement proper log rotation and retention policies to manage the volume of logs efficiently.

• Leverage distributed systems and parallel processing to handle large volumes of logs effectively.

• Use filtering and parsing techniques to extract relevant information ...read more

The task is to find the frequency of subsequent characters in a given input string.

• Iterate through the input string while keeping track of the current character and its frequency.

• If the current character is the same as the previous character, increment the frequency count.

• If the current character is different, append the previous character and its frequency to the output string.

• Repeat until the end of the input string is reached.

Concatenate 3 columns and handle null values in SQL query

• Use CONCAT_WS function to concatenate columns and handle null values

• Provide a separator as the first argument in CONCAT_WS function

• Use IFNULL function to replace null values with a specified value

Actuator in Spring Boot provides production-ready features like monitoring and metrics.

• Actuator is a set of tools provided by Spring Boot to monitor and manage your application.

• Actuator endpoints are URLs that provide information about your application, such as health, metrics, info, etc.

• Examples of actuator endpoints include /actuator/health, /actuator/metrics, /actuator/info, etc.

I am interested in technologies related to artificial intelligence, machine learning, and cloud computing.

• Artificial Intelligence

• Machine Learning

• Cloud Computing

Methods for enabling communication between microservices

• RESTful APIs

• Message queues (e.g. RabbitMQ, Kafka)

• gRPC (Google Remote Procedure Call)

• Service mesh (e.g. Istio, Linkerd)

• Event-driven architecture (e.g. using Apache Kafka)

Coding challenges with screen sharing involve solving programming problems while sharing your screen with an interviewer.

• Prepare by practicing coding challenges beforehand

• Ensure your internet connection and screen sharing software are working properly

• Communicate your thought process and ask questions during the challenge

• Test your code thoroughly before submitting

• Be open to feedback and suggestions from the interviewer

Program to check if sum of digits of a number is prime

• Convert the number to a string to iterate through each digit

• Calculate the sum of digits

• Check if the sum is a prime number

Program to find frequency of words in a sentence

• Split the sentence into words using space as delimiter

• Create a map to store word frequencies

• Iterate through the words and update the map accordingly

• Handle case sensitivity and punctuation if needed

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

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

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

To check load issue and spamming, monitor server performance, analyze traffic patterns, implement CAPTCHA, and use machine learning algorithms.

• Monitor server performance to identify any spikes in traffic or unusual activity

• Analyze traffic patterns to detect any abnormal behavior or patterns consistent with spamming

• Implement CAPTCHA or other verification methods to prevent automated spamming

• Utilize machine learning algorithms to continuously learn and adapt to new spamming tec...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.

Objects are stored in memory in the heap or stack depending on their scope and lifetime.

• Objects with local scope are stored on the stack, while objects with dynamic memory allocation are stored on the heap.

• Primitive data types like int, float are stored on the stack, while complex objects like arrays, classes are stored on the heap.

• Objects stored on the stack have faster access but limited size, while objects on the heap have slower access but can grow dynamically.

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

No, an abstract class can have concrete methods as well.

• An abstract class can have both abstract and concrete methods.

• Abstract methods are meant to be implemented by subclasses, while concrete methods can have a default implementation.

• Having only abstract methods in an abstract class is not a requirement.

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

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

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

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

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

Currying in JavaScript is a technique of transforming a function that takes multiple arguments into a sequence of functions, each taking a single argument.

• Create a function that takes a single argument and returns a new function that takes the next argument.

• Repeat this process until all arguments are received and then return the final result.

• Example: function sum(a) { return function(b) { return function(c) { return function(d) { return a + b + c + d; }; }; }; } sum(1)(2)(3)(...read more

SQL databases are relational databases with structured data and predefined schema, while NoSQL databases are non-relational databases with flexible schema and unstructured data.

• SQL databases use structured query language for defining and manipulating data, while NoSQL databases use different query languages or APIs.

• SQL databases are table-based, with rows and columns, while NoSQL databases can be document-based, key-value pairs, graph databases, etc.

• SQL databases are good for...read more

Cloning a singly linked list with random pointers involves creating a deep copy of the list while maintaining the random pointers.

• Create a new node for each node in the original list and insert it next to the original node.

• Update the random pointers of the new nodes to point to the corresponding new nodes.

• Separate the original and cloned lists by adjusting the next pointers.

Generate permutations of a given string

• Use recursion to generate all possible permutations

• Swap characters in the string to create different permutations

• Base case: when the string length is 1, return the string as a permutation

Find the maximum subarray sum using Kadane's algorithm

• Initialize max_sum and current_sum to 0

• Iterate through the array and update current_sum by adding the current element

• If current_sum becomes negative, reset it to 0

• Update max_sum if current_sum is greater than max_sum

Use GROUP BY to find distinct values in SQL without using the DISTINCT keyword.

• Use GROUP BY clause with all columns in the SELECT statement

• This will group the rows with the same values together, effectively giving distinct values