100+ Software Engineer II Interview Questions and Answers

Divide the horses into groups of 5 and race them. Take the top 2 from each race and race them again. Finally, race the top 2 horses to determine the top 3.

• Divide the horses into 3 groups of 5 and race them.

• Take the top 2 horses from each race and race them again.

• Finally, race the top 2 horses to determine the top 3.

Find minimum steps to make product of array equal to 1 by changing elements by +1,-1,0.

• Calculate number of negative elements and number of zeroes in array.

• If number of negative elements is even, add 1 to all elements.

• If number of negative elements is odd, add 1 to all elements except the smallest negative element.

• Count the number of steps taken to modify the array elements.

• Return the count of steps taken.

Interfaces define a contract for behavior, while abstract classes provide partial implementation.

• Interfaces only define method signatures, while abstract classes can have both abstract and concrete methods.

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

• Interfaces are used for loose coupling and flexibility in design.

• Abstract classes are used for code reuse and to enforce a common implementation among subclasses.

Given an array, print the next greater element for every element.

• Iterate through the array from right to left

• Use a stack to keep track of the greater elements

• Pop elements from the stack until a greater element is found or the stack is empty

• If a greater element is found, it is the next greater element for the current element

• If the stack is empty, there is no greater element for the current element

• Store the next greater element in a result array

• Reverse the result array to get t...read more

C++ is a general-purpose programming language while Objective C is a superset of C used for iOS and macOS development.

• C++ is widely used for developing applications, games, and system software.

• Objective C is primarily used for iOS and macOS development.

• C++ supports both procedural and object-oriented programming paradigms.

• Objective C is an object-oriented language with dynamic runtime features.

• C++ has a larger standard library compared to Objective C.

• Objective C uses a Smallt...read more

Using stream API to find the sum of even numbers from an ArrayList

• Convert the ArrayList to a stream using the stream() method

• Filter the stream to keep only the even numbers using the filter() method

• Use the mapToInt() method to convert the stream of even numbers to an IntStream

• Finally, use the sum() method to calculate the sum of the even numbers

Class container is a class that holds objects of other classes, while class composition is a way to combine multiple classes to create a new class.

• Class container holds objects of other classes, acting as a collection or container.

• Class composition combines multiple classes to create a new class with its own behavior and attributes.

• In class container, the objects are typically stored in a data structure like an array or a list.

• In class composition, the classes are combined by...read more

Stored procedures are used to perform a set of actions, while functions return a single value.

• Stored procedures are precompiled and stored in the database, while functions are compiled at runtime.

• Functions can be used in SQL statements, while stored procedures cannot be used in SQL statements.

• Functions can be called from within stored procedures, but stored procedures cannot be called from within functions.

Developing a custom solution for complex business processes in Sales Cloud

• The business process required complex automation and customization

• The OOB features of Sales Cloud were not sufficient to meet the requirements

• Developed custom Lightning components and Apex code to automate the process

• The solution was thoroughly tested and validated before deployment

Software development design patterns are reusable solutions to common problems encountered in software design.

• Design patterns help in creating maintainable, scalable, and efficient software.

• Singleton design pattern ensures a class has only one instance and provides a global point of access to it.

• Example: Implementing a singleton class in Java -

• public class Singleton { private static Singleton instance; private Singleton() {} public static Singleton getInstance() { if(instance...read more

DSA questions on array and binary tree manipulation

• For printing pairs with target sum, use a hash table to store frequency of elements and check if complement exists

• For converting array to BST, use binary search to find the middle element and recursively build left and right subtrees

• For top view of binary tree, use a queue to traverse the tree level by level and store horizontal distance of nodes

• For minimum number of jumps, use dynamic programming to find minimum jumps requir...read more

Virtual keyword is used to declare a method in a base class that can be overridden in a derived class. Override keyword is used in the derived class to override the implementation of the virtual method.

• Virtual keyword is used in the base class to declare a method that can be overridden in the derived class

• Override keyword is used in the derived class to override the implementation of the virtual method

• Virtual methods provide a way for a base class to define a default implemen...read more

Use regex to extract location and shop name from transaction string.

• Use regular expressions to match patterns for location and shop name.

• Look for keywords like 'at', 'from', 'in' to identify location.

• Consider variations in transaction strings and account for them in regex patterns.

• Example: 'Spent $50 at Starbucks Coffee' -> Location: Starbucks Coffee, Shop Name: Starbucks Coffee

I have worked on relational databases like MySQL and PostgreSQL. DML stands for Data Manipulation Language.

• Worked on MySQL and PostgreSQL databases

• Familiar with writing SQL queries for data manipulation

• DML stands for Data Manipulation Language

Calculate profit and loss by analyzing trade data for each company based on trades and prices.

• Aggregate trade data by company to get total trades and prices.

• Calculate total revenue by multiplying the number of trades by the trade price.

• Determine costs if available; otherwise, assume a baseline cost.

• Profit/Loss = Total Revenue - Total Costs.

• Example: If Company A has 100 trades at $10 each, revenue = 1000. If costs = 800, profit = 200.

Interview questions for Software Engineer II

• Abstract class is a class that cannot be instantiated and can have both abstract and non-abstract methods. Interface is a blueprint of a class that only has abstract methods.

• OOPs concepts include inheritance, polymorphism, encapsulation, and abstraction. Example: Inheritance - a child class inheriting properties and methods from a parent class.

• SOLID principles are Single Responsibility, Open-Closed, Liskov Substitution, Interface Se...read more

Prepared Statements interface is used to prevent SQL injection.

• Prepared Statements interface is used to parameterize the SQL queries.

• It allows the separation of SQL code and user input.

• It helps to prevent SQL injection attacks by automatically escaping special characters.

• Examples: PDO, mysqli, Java PreparedStatement, etc.

A simple API app can be built using Flask to handle requests and display its status.

• Use Flask to create a basic web server: `from flask import Flask`.

• Define a route to handle GET requests: `@app.route('/status')`.

• Return a JSON response indicating the API is running: `return {'status': 'running'}`.

• Run the app with `app.run(debug=True)` to enable debugging.

• Test the API using tools like Postman or curl.

The width of a tree can be calculated by finding the maximum number of nodes at any level.

• Traverse the tree level by level using breadth-first search

• Keep track of the maximum number of nodes at any level

• Return the maximum number of nodes as the width of the tree

Redux is a predictable state container for JavaScript apps.

• Redux is used for managing the state of an application.

• It is commonly used with React to manage the state of components.

• Redux uses a single store to manage the state of an entire application.

• Actions are dispatched to the store to update the state.

• Reducers are used to update the state based on the dispatched actions.

• Functional components can use the useSelector hook to access the state.

• Class components can use the conn...read more

Questions on software engineering concepts, previous roles and responsibilities, and personal strengths and weaknesses.

• ConcurrentModificationException: occurs when a collection is modified while being iterated over

• Vertical Scaling vs Horizontal Scaling: vertical scaling involves adding more resources to a single machine, while horizontal scaling involves adding more machines to a system

• Roles and responsibilities in previous org: discuss previous job titles and duties

• Strengths...read more

SOLID principles are a set of five design principles for writing maintainable and scalable code.

• Single Responsibility Principle (SRP) - a class should have only one reason to change

• Open-Closed Principle (OCP) - a class should be open for extension but closed for modification

• Liskov Substitution Principle (LSP) - subtypes should be substitutable for their base types

• Interface Segregation Principle (ISP) - clients should not be forced to depend on interfaces they do not use

• Depend...read more

Program to find the second largest element from a 4-digit number

• Convert the number to a string and split it into an array of characters

• Sort the array in descending order

• Return the second element of the array

Find indices of two numbers in an array that sum up to a given target.

• Use a hash map to store the difference between the target and each element's value.

• Iterate through the array and check if the current element exists in the hash map.

• If it exists, return the indices of the current element and the element from the hash map.

• Example: For array [2, 7, 11, 15] and target 9, return [0, 1] since 2 + 7 = 9.

Session authentication in websites and storing large databases using hashing.

• Session authentication in websites involves creating a unique session ID for each user upon login and storing it in a cookie or server-side session storage.

• The session ID is then used to authenticate subsequent requests from the user.

• Large databases can be stored using hashing techniques such as sharding, consistent hashing, and hash tables.

• Sharding involves dividing the database into smaller partiti...read more

Singleton design pattern restricts the instantiation of a class to a single instance and provides a global point of access to it.

• Used when only one instance of a class is required throughout the system

• Provides a global point of access to the instance

• Implemented using a private constructor, static method, and static variable

• Example: Logger class, Database connection class

SOLID design principles and Design Patterns are used to create maintainable and scalable software.

• SOLID principles help in creating loosely coupled and modular code.

• Design Patterns provide reusable solutions to common software problems.

• Examples of SOLID principles include Single Responsibility, Open/Closed, and Liskov Substitution.

• Examples of Design Patterns include Factory, Singleton, and Observer.

• Using SOLID principles and Design Patterns can improve code quality, reduce bu...read more