40+ Mts Software Engineer Interview Questions and Answers

Data structures are ways to organize and store data for efficient access and modification.

• Data structures include arrays, linked lists, stacks, queues, trees, and graphs.

• Arrays are fixed-size, contiguous memory locations; linked lists are dynamic and consist of nodes.

• Linear data structures (like arrays and linked lists) have a sequential relationship; non-linear (like trees and graphs) do not.

• Stacks follow Last In First Out (LIFO) principle (e.g., browser history); queues fol...read more

OOP is a programming paradigm based on objects, encapsulating data and behavior, enhancing modularity and reusability.

• OOP stands for Object-Oriented Programming, focusing on objects that combine data and methods.

• Abstraction hides complex implementation details, while encapsulation restricts access to certain components.

• A virtual function is a member function in a base class that you can override in a derived class; an interface is a contract for classes to implement.

• Polymorph...read more

Addressing conflicts with a developer requires communication, understanding, and collaboration to find a resolution.

• Initiate a one-on-one conversation to understand their perspective.

• Use 'I' statements to express how the conflict affects your work, e.g., 'I feel overwhelmed when deadlines are missed.'

• Seek common ground by discussing shared goals and objectives.

• Propose solutions collaboratively, such as adjusting timelines or redistributing tasks.

• Involve a neutral third party,...read more

OOP is a programming paradigm based on objects, enabling abstraction, encapsulation, inheritance, and polymorphism.

• OOP stands for Object-Oriented Programming, focusing on objects that combine data and behavior.

• Structs are value types, while unions can store different data types but only one at a time.

• Abstraction hides complex implementation details, while encapsulation restricts access to certain components.

• Example of struct: 'struct Point { int x; int y; };'. Example of unio...read more

Return k most frequent strings from an array of strings

• Use a hashmap to store the frequency of each string in the array

• Sort the hashmap by frequency in descending order

• Return the first k keys from the sorted hashmap

The task is to add two numbers represented as linked lists and return the result as a new linked list.

• Traverse both linked lists simultaneously, starting from the head

• Add the corresponding nodes from both lists along with any carry from the previous addition

• If the sum is greater than 9, set the carry to 1 and take the remainder as the new node value

• Move to the next nodes in both lists

• Continue this process until both lists are exhausted

• If there is still a carry remaining, add ...read more

Find the missing character in two strings with linear time complexity and constant space complexity.

• Iterate through both strings simultaneously and XOR the ASCII values of characters.

• The missing character will be the XOR result with the ASCII value of the last character in the longer string.

• Example: s1 = 'abcd', s2 = 'abcde', missing character is 'e'.

Apache Cassandra is a persistent in-memory key-value store optimized for write-heavy workloads using SSTables and compaction.

• Apache Cassandra is a popular choice for write-heavy workloads due to its distributed architecture and support for SSTables.

• SSTables (Sorted String Tables) are used to store data on disk in a sorted manner, allowing for efficient read and write operations.

• Compaction in Apache Cassandra helps to merge and organize SSTables, reducing disk space usage and ...read more

Core concepts of Spring include dependency injection, aspect-oriented programming, and Spring MVC. Spring Boot simplifies the setup and configuration of Spring applications. Java 8 introduced lambda expressions and streams, while Java 17 added features like sealed classes and pattern matching. Object-oriented programming concepts include inheritance, polymorphism, encapsulation, and abstraction.

• Spring core concepts: dependency injection, aspect-oriented programming, Spring MV...read more

IP address is converted to URL through DNS resolution process involving multiple steps.

• IP address is obtained from the domain name system (DNS) server when a user enters a URL in a web browser.

• The DNS server looks up the IP address associated with the URL in its database.

• The DNS server then returns the IP address to the user's device, allowing it to establish a connection to the server hosting the website.

• For example, when a user enters 'www.google.com' in a browser, the DNS ...read more

C# List is a generic collection while Array List is non-generic. List is more flexible and efficient due to its dynamic resizing.

• List is a generic collection in C# that provides dynamic resizing and type safety.

• ArrayList is a non-generic collection that stores objects and requires boxing and unboxing for value types.

• List is more efficient in terms of performance and memory usage compared to ArrayList.

Java is a popular programming language used for developing various applications. Concurrency errors occur when multiple threads access shared resources simultaneously.

• Java is a high-level, object-oriented programming language known for its platform independence.

• Concurrency errors in Java can be solved using synchronization mechanisms like synchronized blocks, locks, and atomic variables.

• Examples of solving concurrency errors in Java include using synchronized keyword to prote...read more

Accelerometer, gyroscope, heart rate sensor, GPS, temperature sensor, etc.

• Accelerometer: measures acceleration

• Gyroscope: measures orientation and rotation

• Heart rate sensor: measures heart rate

• GPS: tracks location

• Temperature sensor: measures body temperature

Search for target value in a sorted rotated array efficiently.

• Use binary search to find the pivot point where the array is rotated.

• Then perform binary search on the appropriate half of the array to find the target value.

• Handle cases where the target value is at the pivot point or not found.

Yes, I have completed multiple projects in Python.

• Developed a web scraping tool using BeautifulSoup library

• Created a data analysis program using pandas and numpy

• Built a machine learning model using scikit-learn

I2C (Inter-Integrated Circuit) is a serial communication protocol used to connect multiple devices in a master-slave configuration.

• I2C uses two wires for communication - SDA (data line) and SCL (clock line).

• Devices on the I2C bus are either masters or slaves, with the master initiating communication.

• Each device on the bus has a unique address, allowing multiple devices to communicate on the same bus.

• I2C supports multiple speeds (standard mode, fast mode, etc.) for communicati...read more

Design a coffee machine with various functionalities like brewing different types of coffee, adding milk, and adjusting temperature.

• Include options for different types of coffee (espresso, latte, cappuccino)

• Allow users to add milk or cream to their coffee

• Provide options to adjust the temperature of the coffee

• Include a water reservoir for brewing coffee

• Add a display screen for user interaction

Find the maximum product sub-array in an array of integers.

• Iterate through the array and keep track of the maximum product ending at each index.

• Also keep track of the minimum product ending at each index, as negative numbers can change the sign of the product.

• Update the maximum product by taking the maximum of the current element, current element times the maximum product ending at previous index, and current element times the minimum product ending at previous index.

Sort zeros to the end of the array of strings

• Iterate through the array and move all zeros to the end

• Use two pointers approach to swap elements

• Example: Input: ['1', '0', '3', '0', '5'], Output: ['1', '3', '5', '0', '0']

Learn how to read command-line parameters in Python using sys and argparse modules.

• Use the sys module: Import sys and access sys.argv for command-line arguments.

• Example: import sys; print(sys.argv) to see all arguments passed.

• Use argparse for more complex parsing: Import argparse and define expected arguments.

• Example: parser = argparse.ArgumentParser(); parser.add_argument('--name'); args = parser.parse_args(); print(args.name) to get the value.

I have learnt to adapt my strategy based on project requirements and team dynamics.

• I prioritize tasks based on their impact on project goals

• I communicate effectively with team members to ensure everyone is on the same page

• I am flexible and open to feedback, making adjustments as needed

• I have learned to balance short-term goals with long-term objectives

• For example, on a recent project, I had to adjust my strategy when a key team member left unexpectedly. I reassigned tasks and...read more

The island problem on LeetCode involves finding the number of connected islands in a grid of 1s and 0s.

• Use depth-first search (DFS) or breadth-first search (BFS) to traverse the grid and count the number of islands.

• Keep track of visited cells to avoid redundant calculations.

• Consider diagonal movements if specified in the problem.

• Example: Given grid = [[1,1,0,0],[0,1,0,1],[1,0,0,1]], the number of islands is 3.

A Python program to reverse a singly linked list using iterative and recursive methods.

• Define a Node class to represent each element in the linked list.

• Create a LinkedList class to manage the linked list operations.

• Implement an iterative method to reverse the linked list by adjusting pointers.

• Implement a recursive method that reverses the linked list by traversing to the end and adjusting pointers on the way back.

• Example: For a linked list 1 -> 2 -> 3 -> None, the reversed li...read more

Use a hash set to find two elements in an array that sum up to a given value x.

• Create a hash set to store elements as you iterate through the array.

• For each element, check if the difference between x and the current element exists in the hash set.

• If it does, return the current element and the difference as the two elements that sum up to x.

As a fresher, I focus on my academic projects, internships, and skills to communicate my potential effectively.

• Academic Projects: Developed a web application using React and Node.js during my final year, showcasing my coding skills.

• Internships: Completed a summer internship at XYZ Corp, where I contributed to a team project, enhancing my teamwork abilities.

• Technical Skills: Proficient in Java, Python, and SQL, which I highlighted in my resume and during interviews.

• Soft Skills...read more

OOPS concepts refer to Object-Oriented Programming principles like Inheritance, Encapsulation, Polymorphism, and Abstraction.

• Inheritance: Allows a class to inherit properties and behavior from another class.

• Encapsulation: Bundling data and methods that operate on the data into a single unit.

• Polymorphism: Ability to present the same interface for different data types.

• Abstraction: Hiding the complex implementation details and showing only the necessary features.

Scaling a system involves increasing its capacity to handle more load or users.

• Identify bottlenecks and optimize them

• Use load balancing to distribute traffic evenly

• Implement caching to reduce database load

• Horizontal scaling by adding more servers

• Vertical scaling by upgrading hardware