100+ Software Engineer Intern Interview Questions and Answers

A SQL query to move a table from one schema to another.

• Use the ALTER TABLE statement to rename the table and move it to the new schema.

• Specify the new schema name in the ALTER TABLE statement.

• Ensure that the user executing the query has the necessary privileges to perform the operation.

The program offers hands-on experience with cutting-edge technologies and provides mentorship from industry experts.

• Access to cutting-edge technologies

• Mentorship from industry experts

• Hands-on experience with real-world projects

I used Apache Spark to process large datasets and perform complex data transformations during my internship.

• Implemented Spark jobs to analyze customer behavior data and generate insights for marketing campaigns

• Utilized Spark SQL for querying and aggregating data from multiple sources

• Optimized Spark jobs by tuning configurations and partitioning data for better performance

My favorite programming language is Python due to its simplicity, readability, and versatility.

• Python is known for its clean and readable syntax, making it easy to learn and use.

• Python has a vast standard library and many third-party packages, allowing for rapid development.

• Python is versatile and can be used for web development, data analysis, machine learning, and more.

Agile model is an iterative approach to software development that emphasizes flexibility and customer satisfaction.

• Agile model involves continuous collaboration between cross-functional teams and customers

• It prioritizes working software over comprehensive documentation

• It allows for changes and adjustments to be made throughout the development process

• Examples of agile methodologies include Scrum, Kanban, and Extreme Programming (XP)

I have experience working with databases, including designing schemas, writing queries, and optimizing performance.

• Designed database schemas for various projects

• Written complex SQL queries to retrieve and manipulate data

• Optimized database performance by indexing tables and tuning queries

• Worked with relational databases like MySQL and PostgreSQL

• Familiar with NoSQL databases like MongoDB

Abstraction is the process of hiding complex implementation details and exposing only the necessary information.

• Abstraction helps in reducing complexity and increasing efficiency.

• It allows us to focus on the essential features of an object or system.

• For example, a car's dashboard abstracts the complex workings of the car's engine and presents only the necessary information to the driver.

Merge two sorted lists up to length k

• Create a new list to store the merged result

• Iterate through both lists up to length k, comparing elements and adding the smaller one to the new list

• Handle cases where one list is shorter than k

AI stands for Artificial Intelligence, ML stands for Machine Learning, and deep learning is a subset of ML that uses neural networks to model and solve complex problems.

• AI is the simulation of human intelligence processes by machines, such as learning, reasoning, and self-correction.

• ML is a subset of AI that focuses on the development of algorithms that can learn from and make predictions or decisions based on data.

• Deep learning is a subset of ML that uses neural networks wit...read more

Application deployment involves transferring code from development environment to production servers.

• Choose a deployment method (e.g. manual, automated, continuous deployment)

• Prepare the application for deployment by packaging it with necessary dependencies

• Select a deployment environment (e.g. cloud, on-premises)

• Transfer the packaged application to the deployment environment

• Configure the deployment environment (e.g. set up databases, configure servers)

• Run tests to ensure the ...read more

Binary search in a sorted rotated array with duplicates present.

• Perform a modified binary search by checking both ends of the array for duplicates

• Handle cases where duplicates are present at the start, end, or middle of the array

• Consider cases where the array is rotated multiple times

Binary search in a sorted rotated array with no duplicates.

• Find the pivot point where the array is rotated.

• Determine which half of the array to search based on the target value and pivot point.

• Perform binary search in the selected half of the array.

Iterate through each row and count the number of 1s, return the row with the maximum count.

• Iterate through each row of the matrix

• Count the number of 1s in each row

• Track the row with the maximum count of 1s

Virtual memory is a memory management technique that allows a computer to compensate for physical memory shortages by temporarily transferring data from RAM to disk storage.

• Virtual memory allows programs to use more memory than is physically available on the computer.

• It helps in multitasking by allowing multiple programs to run simultaneously without running out of memory.

• Virtual memory uses a combination of RAM and disk space to store data temporarily.

• When a program needs mo...read more

Hashmaps and dictionaries are data structures used to store key-value pairs for efficient retrieval and storage.

• Hashmaps and dictionaries are commonly used in programming to store and retrieve data based on a unique key.

• They offer fast lookup times, typically O(1) on average, making them ideal for scenarios where quick access to data is required.

• Examples of using hashmaps include storing user information with a unique user ID as the key, or mapping words to their frequencies ...read more

Use Spring Boot and Hibernate to connect database to frontend

• Create a Spring Boot application with dependencies for Spring Data JPA and Hibernate

• Define entity classes representing database tables and annotate them with @Entity

• Create a repository interface extending JpaRepository to perform CRUD operations

• Configure application.properties file with database connection details

• Use Hibernate to automatically generate database schema based on entity classes

A stored procedure is a precompiled set of SQL statements that can be executed on a database server.

• Stored procedures are used to encapsulate and execute complex database operations.

• They can be used to improve performance by reducing network traffic.

• Stored procedures can be parameterized and reused across multiple applications.

• They provide a level of security by allowing access to the database only through the procedure.

• Examples: Creating a stored procedure to insert data int...read more

An AND gate using MOSFETs is a digital logic gate that outputs a high signal only when all input signals are high.

• An AND gate using MOSFETs typically consists of multiple MOSFETs connected in series.

• When all input signals are high, the output signal is high.

• Examples of MOSFETs commonly used in AND gates include NMOS and PMOS transistors.

Use slicing to reverse a Python string

• Use string slicing with a step of -1 to reverse the string

• Example: 'hello'[::-1] will return 'olleh'

Find the missing number in an array of integers from 1 to n.

• Create a hash set to store the numbers in the array

• Loop through the numbers from 1 to n and check if they are in the hash set

• Return the number that is not in the hash set

Level Order Traversal for Binary Tree is a method to visit all nodes level by level starting from the root.

• Use a queue data structure to keep track of nodes at each level

• Start by pushing the root node into the queue

• While the queue is not empty, dequeue a node, visit it, and enqueue its children

Joins are used to combine data from two or more tables based on a related column.

• Joins are used to retrieve data from multiple tables in a single query.

• They are performed using the JOIN keyword followed by the name of the table to be joined.

• Common types of joins include INNER JOIN, LEFT JOIN, RIGHT JOIN, and FULL OUTER JOIN.

• Joins are based on a related column between the tables, known as the join condition.

• The result of a join is a new table that combines the columns from bot...read more

Implement list creation in data structures and algorithms

• Use an array to store the elements of the list

• Implement functions to add, remove, and access elements in the list

• Consider using a linked list for more efficient insertion and deletion operations

Tuple is a data structure that stores a fixed number of elements, while delete command is used to remove data from a database table.

• Tuple is used to store multiple values in a single variable, while delete command is used to remove specific rows from a database table.

• Tuples are immutable, meaning their values cannot be changed once they are set, while delete command permanently removes data from a table.

• Example: Tuple (1, 'apple', 3.14) vs. DELETE FROM table_name WHERE condit...read more

Find the next greater element for each element in an array.

• Use a stack to keep track of elements without a next greater element.

• Iterate through the array and compare elements with the top of the stack.

• Update the stack with the current element if it is greater than the top element.

React.js is a JavaScript library used for building user interfaces.

• React allows developers to create reusable UI components.

• It uses a virtual DOM for efficient rendering and updates.

• React is often used in conjunction with other libraries and frameworks, such as Redux and Next.js.

• It is widely used in web development for creating single-page applications and dynamic user interfaces.

• React was developed by Facebook and is open-source.

LRU cache memory can be implemented using a linked list to store and manage recently used items efficiently.

• Use a doubly linked list to keep track of the order of items based on their usage.

• When an item is accessed, move it to the front of the list to indicate it is the most recently used.

• If the cache is full, remove the least recently used item from the end of the list.

• Maintain a hashmap for quick access to items in the linked list.

Topological Sort is a linear ordering of vertices in a directed acyclic graph.

• It is used to find a linear ordering of elements that have dependencies.

• It is based on the concept of DFS (Depth First Search).

• It can be implemented using both DFS and BFS (Breadth First Search).

• It is commonly used in scheduling jobs, resolving dependencies, and compiling code.

• Example: Topological sorting of courses to take in a college based on prerequisites.

Rotate array by d places

• Create a temporary array to store elements to be rotated

• Shift elements in the original array to the left by d places

• Copy elements from the temporary array to the original array at the end

Use SQL query to print the first 1000 rows using the id column

• Use SELECT statement to retrieve data from the table

• Use ORDER BY clause to sort the data by id column

• Limit the result set to 1000 rows using LIMIT clause

A 2 player chess game with standard rules and GUI

• Implement standard chess rules and moves

• Create a GUI for players to interact with the game

• Allow players to make moves and track game progress

• Incorporate checkmate and stalemate conditions

• Implement a timer for each player's turn

Developed an Android app for tracking daily expenses

• Used Java and Android Studio for development

• Implemented SQLite database for storing data

• Included charts and graphs for visual representation of expenses

Left join includes all records from the left table and matching records from the right table, while right join includes all records from the right table and matching records from the left table.

• Left join keeps all records from the left table, even if there are no matches in the right table.

• Right join keeps all records from the right table, even if there are no matches in the left table.

• Example: If we have a table of employees and a table of departments, a left join will inclu...read more

Use SQL query with ORDER BY and LIMIT to find the 2nd highest salary.

• Use ORDER BY clause to sort salaries in descending order

• Use LIMIT 1,1 to skip the first highest salary and get the second highest salary

To find the minimum element in a stack in O(1) space, use an auxiliary stack to keep track of the minimum element at each step.

• Create an auxiliary stack to store the minimum element at each step.

• When pushing an element onto the main stack, compare it with the top element of the auxiliary stack and push the smaller one onto the auxiliary stack.

• When popping an element from the main stack, also pop the top element from the auxiliary stack.

• To get the minimum element, simply retur...read more

SSMS is a management tool for SQL Server, SSIS is an ETL tool, and SSAS is a BI tool for analyzing data.

• SSMS (SQL Server Management Studio) is a graphical management tool for SQL Server.

• SSIS (SQL Server Integration Services) is an ETL (Extract, Transform, Load) tool used for data integration and workflow applications.

• SSAS (SQL Server Analysis Services) is a BI (Business Intelligence) tool used for analyzing and reporting data.

• SSMS is used for managing databases, creating and ...read more

React HOC's are higher-order components that allow for code reuse and logic abstraction in React applications.

• HOC's are functions that take a component and return a new component with additional props or functionality.

• They are commonly used for tasks like authentication, logging, and conditional rendering.

• Example: withAuth HOC can be used to protect routes by checking if a user is authenticated before rendering the component.

Google search works by crawling and indexing web pages, and then ranking them based on relevance and quality.

• Google uses web crawlers to discover and index web pages.

• The search algorithm ranks pages based on relevance to the search query.

• Factors like keywords, backlinks, and user experience influence rankings.

• Google constantly updates its algorithm to improve search results.

• Google also considers user location and search history for personalized results.

The schema of my project is designed to efficiently store and retrieve data for a web application.

• Use relational database to store structured data

• Create tables for different entities like users, products, orders

• Establish relationships between tables using foreign keys

• Use indexes to optimize query performance

Find the maximum sum of a path in a binary tree.

• Traverse the tree recursively and calculate the maximum sum of left and right subtrees.

• Update the maximum sum if the current node value + left subtree sum + right subtree sum is greater.

• Return the maximum sum found.

• Consider negative values in the tree as well.

Localstorage is a web storage feature in browsers that allows websites to store data locally on a user's device.

• Localstorage is a key-value storage system that allows websites to store data on a user's device.

• Data stored in localstorage persists even after the browser is closed.

• Localstorage is limited to about 5MB of data per domain.

• It is commonly used for storing user preferences, session data, and caching.

• Example: localStorage.setItem('username', 'john_doe');

OOPs concepts are the fundamental principles of Object-Oriented Programming.

• Encapsulation - binding data and functions that manipulate them

• Inheritance - creating new classes from existing ones

• Polymorphism - ability of objects to take on multiple forms

• Abstraction - hiding implementation details and showing only functionality

• Examples: class, object, inheritance, encapsulation, polymorphism, abstraction

Sort a stack using another stack

• Create an empty temporary stack

• Pop elements from the original stack and push them onto the temporary stack in sorted order

• Pop elements from the temporary stack back to the original stack

F1 score is a measure of a test's accuracy that considers both the precision and recall of the test.

• F1 score is the harmonic mean of precision and recall.

• It is calculated using the formula: 2 * (precision * recall) / (precision + recall)

• F1 score ranges from 0 to 1, where 1 is the best possible score.

• It is commonly used in binary classification tasks.

Polling is a technique used to continuously check the status of a resource or process.

• Polling involves sending out periodic requests to check for updates or changes.

• It is commonly used in software development to monitor changes in data or resources.

• Polling can be synchronous or asynchronous, depending on the implementation.

• Examples of polling include checking for new emails in an inbox or updating a live chat feed.

Bubble sort has a time complexity of O(n^2) in the worst case scenario.

• Bubble sort compares adjacent elements and swaps them if they are in the wrong order.

• It continues to iterate through the array until no more swaps are needed.

• The worst case time complexity of bubble sort is O(n^2) where n is the number of elements in the array.

• Example: If we have an array of 5 elements, bubble sort would take 25 comparisons in the worst case.

BFS and DFS are traversal algorithms used in graph theory to visit all nodes in a graph.

• BFS (Breadth-First Search) visits nodes level by level, while DFS (Depth-First Search) goes as deep as possible before backtracking.

• BFS uses a queue data structure, while DFS uses a stack or recursion.

• Example: BFS traversal of a graph starting from node A: A -> B -> C -> D -> E

• Example: DFS traversal of a graph starting from node A: A -> B -> D -> E -> C