100+ Software Engineer III Interview Questions and Answers

Find the highest floor from where an egg won't break, given k floors and n eggs.

• Use binary search to minimize the number of drops.

• Start from the middle floor and drop the egg.

• If it breaks, search in the lower half, else search in the upper half.

• Repeat until the highest floor is found.

Graph

• Use a graph data structure to represent people as nodes and friend relations as edges

• Each person can be represented as a node with their unique identifier

• Friend relations can be represented as directed edges between nodes

• This allows for efficient traversal and retrieval of friend connections

Custom stack with methods to return min and max elements

• Implement a stack using an array or linked list

• Track the minimum and maximum elements using additional variables

• Update the minimum and maximum variables during push and pop operations

• Implement methods to return the minimum and maximum elements

Explanation of useState, useEffect, useMemo, and useCallback hooks in React functional components.

• useState is used to manage state in functional components

• useEffect is used for handling side effects like data fetching, subscriptions, etc.

• useMemo is used for performance optimization by memoizing expensive calculations

• useCallback is used for memoizing functions to prevent unnecessary re-renders

• These hooks enhance functional components by providing state management, side effect ...read more

Given a tree and a node, print all ancestors of Node

• Start from the given node and traverse up the tree

• While traversing, keep track of the parent nodes

• Print the parent nodes as you traverse up until reaching the root

To add and manipulate elements in arrays using JavaScript, you can use array methods like splice() and slice().

• Use the splice() method to insert elements into an array at a specific index. For example, arr.splice(index, 0, 'watermelon') will insert 'watermelon' at the specified index without removing any elements.

• To manipulate elements in an array, you can use methods like splice() to remove elements or slice() to extract a portion of the array.

• Remember that arrays in JavaScr...read more

Lifecycle methods in class components and their hooks equivalents manage component behavior during mounting, updating, and unmounting.

• componentDidMount: Runs after the component is mounted. Use useEffect(() => { /* code */ }, []); for hooks.

• componentDidUpdate: Invoked after updates. Use useEffect(() => { /* code */ }, [dependencies]); for hooks.

• componentWillUnmount: Cleanup before unmounting. Use return function in useEffect(() => { return () => { /* cleanup */ }; }, []);.

Object-oriented concepts involve creating classes and objects to organize and structure code.

• Classes define the properties and behaviors of objects

• Objects are instances of classes that can interact with each other

• Inheritance allows for the creation of subclasses that inherit properties and behaviors from a parent class

• Polymorphism allows for objects to take on multiple forms and behave differently depending on the context

• Encapsulation involves hiding the implementation detail...read more

CORS is a security feature that allows or restricts web applications from making requests to different domains.

• Cross-Origin Resource Sharing (CORS): A mechanism that allows restricted resources on a web page to be requested from another domain outside the domain from which the first resource was served.

• HTTP Headers: CORS uses HTTP headers to tell browsers to give a web application access to resources from a different origin. Key headers include 'Access-Control-Allow-Origin'.

• P...read more

Microservices are implemented using RESTful APIs and message brokers for asynchronous communication.

• RESTful APIs are used for synchronous communication between microservices.

• Message brokers like Kafka or RabbitMQ are used for asynchronous communication.

• Microservices communicate with each other using HTTP requests and responses.

• Each microservice has its own database and communicates with other microservices through APIs.

• Microservices are loosely coupled and can be developed an...read more

I break down the problem into smaller parts and research each part to find a solution.

• Identify the problem and its requirements

• Break down the problem into smaller parts

• Research each part to find a solution

• Try different approaches and test them

• Collaborate with colleagues or seek help from online communities

A program to simulate a race with 5 people using multithreading and determine the winner.

• Create a class for the race participants

• Implement the Runnable interface for each participant

• Use a thread pool to manage the threads

• Start all threads simultaneously

• Wait for all threads to finish

• Determine the winner based on the finishing time

I follow the MVC design pattern as it separates concerns and promotes code reusability.

• MVC separates the application into Model, View, and Controller components.

• Model represents the data and business logic.

• View represents the user interface.

• Controller handles user input and updates the model and view accordingly.

• MVC promotes code reusability and maintainability.

• Example: Ruby on Rails framework follows MVC pattern.

The OSI model has 7 layers. OSI or TCP/UDP depends on the application. OSI is used for theoretical understanding while TCP/UDP is used for practical implementation.

• The 7 layers of OSI model are Physical, Data Link, Network, Transport, Session, Presentation, and Application.

• OSI model is used for theoretical understanding of networking concepts.

• TCP/UDP are used for practical implementation of networking protocols.

• TCP is used for reliable data transfer while UDP is used for fast...read more

Compile time polymorphism is method overloading, while run time polymorphism is method overriding. Multiple inheritance is not supported in Java.

• Compile time polymorphism is achieved through method overloading, where multiple methods have the same name but different parameters.

• Run time polymorphism is achieved through method overriding, where a subclass provides a specific implementation of a method that is already defined in its superclass.

• Java does not support multiple inhe...read more

Use a custom Comparator to sort names with Roman numerals as last names in Java.

• Create a custom Comparator that splits the names into parts and compares the Roman numerals separately.

• Use regular expressions to identify and extract the Roman numerals from the last names.

• Implement the Comparator interface and override the compare method to sort the names based on the Roman numerals.

• Example: Input array - ['John Smith III', 'Alice Brown II', 'David Lee IV']

Efficiently processing millions of records requires strategic batching and optimization techniques.

• Use Batch Apex to process records in manageable chunks, leveraging the execute method to handle 50k records at a time.

• Implement a Queueable Apex pattern to chain multiple jobs, allowing for asynchronous processing of large datasets.

• Utilize Salesforce's Bulk API for handling large volumes of records, which can process up to 10,000 records per request.

• Consider partitioning the dat...read more

Spring scopes define the lifecycle and visibility of beans in a Spring application, impacting their creation and management.

• Singleton Scope: A single instance of the bean is created and shared across the entire Spring container.

• Prototype Scope: A new instance of the bean is created each time it is requested from the container.

• Request Scope: A new bean instance is created for each HTTP request, suitable for web applications.

• Session Scope: A new bean instance is created for eac...read more

Print unique numbers from given array of strings.

• Convert array of strings to array of integers.

• Use a set to store unique numbers.

• Iterate through array and add numbers to set if not already present.

• Print out the unique numbers from the set.

Design a Java-like Garbage Collector with minimal configurations.

• Choose a garbage collection algorithm (e.g. mark-and-sweep, copying, generational)

• Determine the heap size and divide it into regions (e.g. young, old, permanent)

• Implement a root set to keep track of live objects

• Set thresholds for garbage collection (e.g. occupancy, time)

• Implement the garbage collection algorithm and test for memory leaks

Mocking components in Jest for testing with props and named exports

• Use jest.mock() to mock components and their exports

• For handling props, use jest.fn() to create mock functions and pass them as props to the component being tested

• For named exports, use jest.mock() with a second argument to specify the module's exports

Request flows in Spring Boot MVC, ways to instantiate a bean, and handling Java out-of-memory exception.

• Request flows in Spring Boot MVC: DispatcherServlet receives HTTP request, HandlerMapping maps request to appropriate controller, Controller processes request and returns response.

• Ways to instantiate a bean: Constructor injection, setter injection, and using the @Bean annotation.

• Handling Java out-of-memory exception: Analyze memory usage, increase heap size, optimize code, ...read more

I would use a hash table for efficient searching of a lot of data.

• Hash tables provide constant time complexity for search operations.

• They use a hash function to map keys to array indices, allowing for quick retrieval of data.

• Examples of hash table implementations include dictionaries in Python and HashMaps in Java.

Segmentation fault occurs when a program tries to access memory it doesn't have permission to access.

• Segmentation fault occurs when a program tries to access memory outside of its allocated space.

• Compiler detects segmentation faults by checking memory access permissions during compilation.

• Segmentation faults are typically caused by dereferencing a null pointer or accessing an out-of-bounds array element.

Implement a basic data grid component using machine coding

• Start by defining the structure of the data grid component

• Implement functions for adding, updating, and deleting data in the grid

• Include features like sorting, filtering, and pagination

• Consider performance optimizations for handling large datasets

• Test the data grid component with sample data to ensure functionality

Memoization is a technique used in programming to store the results of expensive function calls and return the cached result when the same inputs occur again.

• Memoization helps improve the performance of a function by caching its results.

• It is commonly used in dynamic programming to optimize recursive algorithms.

• Example: Memoizing a Fibonacci function to avoid redundant calculations.

Find a coupon for a given category in a category tree, falling back to parent's coupon if necessary.

• Traverse the category tree starting from the given category

• Check if the current category has a coupon, if not move up to its parent

• Repeat until a coupon is found or reach the root category