300+ Walmart Interview Questions and Answers

PropTypes are a way to type-check props in React components to ensure they are passed correctly.

• Used in React to specify the data type of props passed to a component

• Helps catch bugs by providing warnings if incorrect data types are passed

• Can be defined using PropTypes library or as static properties in a component

Select single retrieves only the first row that meets the condition, while select end select retrieves all rows that meet the condition.

• Select single is used when only one row is expected to be returned.

• Select end select is used when multiple rows are expected to be returned.

• Select single is more efficient as it stops processing after finding the first row.

• Select end select is used with loop statements to process multiple rows.

• Example: SELECT * FROM table WHERE condition INTO...read more

To reduce model inference latency, optimize model architecture, use efficient algorithms, batch processing, and deploy on high-performance hardware.

• Optimize model architecture by reducing complexity and removing unnecessary layers

• Use efficient algorithms like XGBoost or LightGBM for faster predictions

• Implement batch processing to make predictions in bulk rather than one at a time

• Deploy the model on high-performance hardware like GPUs or TPUs

Detect if there is a loop in a graph.

• Use Depth First Search (DFS) to traverse the graph.

• If a node is visited twice during DFS, then there is a loop.

• Maintain a visited set to keep track of visited nodes.

• If a node is already in the visited set, then there is a loop.

SCC stands for Source Code Control. It is a system used to manage and track changes to source code files.

• SCC helps developers collaborate on code by providing version control and tracking changes.

• Popular SCC tools include Git, SVN, and Mercurial.

• SCC allows developers to revert to previous versions of code, track changes made by team members, and merge code changes seamlessly.

• SCC helps in maintaining code integrity and ensuring that the latest version of code is always availab...read more

Collections are essential for efficient data manipulation in Python. A strong grasp of collections is crucial for a data engineer.

• Familiarity with lists, tuples, sets, and dictionaries

• Understanding of when to use each collection type

• Ability to manipulate and iterate through collections

• Knowledge of built-in collection methods and functions

• Experience with third-party collection libraries like NumPy and Pandas

Remove leaf nodes of a tree

• Traverse the tree in postorder fashion

• For each node, check if it is a leaf node (both children are null)

• If it is a leaf node, remove it by setting its parent's reference to null

Increasing sales can be achieved by implementing effective marketing strategies, improving customer service, offering promotions, and expanding the product line.

• Implement targeted marketing campaigns to reach potential customers

• Provide excellent customer service to retain existing customers and attract new ones

• Offer promotions such as discounts, buy-one-get-one-free deals, or loyalty programs to incentivize purchases

• Expand the product line to cater to a wider range of custome...read more

Successfactors API and integration are crucial for efficient HR management.

• Successfactors API allows for seamless integration with other HR systems.

• Integration can automate processes such as onboarding and offboarding.

• API can be used to extract data for reporting and analysis.

• Integration can improve data accuracy and reduce manual errors.

• Examples of integrations include SAP ERP, Workday, and Salesforce.

Implementing LRU Cache without using LinkedHashMap

• Use a doubly linked list to maintain the order of keys based on their recent usage

• Use a hashmap to store key-value pairs for quick access

• When a new key is accessed, move it to the front of the linked list and update the hashmap accordingly

• When the cache is full, remove the least recently used key from the end of the linked list and hashmap

Python program to count the number of words in a file.

• Open the file using 'with open(file_path, 'r') as file:'

• Read the contents of the file using 'file.read()'

• Split the contents into words using 'split()'

• Count the number of words using 'len()'

Cycle detection in graph involves detecting if there is a cycle present in a graph data structure.

• Use Depth First Search (DFS) or Breadth First Search (BFS) to detect cycles in a graph.

• Maintain a visited set to keep track of visited nodes and a recursion stack to keep track of nodes in the current path.

• If a node is visited again and is in the recursion stack, then a cycle is detected.

• Example: Detecting a cycle in a directed graph using DFS.

String programs to reverse and duplicate an array of strings.

• Use a loop to iterate through each string in the array.

• To reverse a string, use the built-in reverse() method or loop through the string backwards.

• To duplicate a string, use the concat() method or the + operator.

• Remember to store the reversed or duplicated string in a new variable or array.

A note taking app that allows users to create, edit, and organize their notes.

• Implement a user interface for creating and editing notes

• Include features like text formatting, image attachments, and voice recordings

• Provide options for organizing notes into folders or categories

• Include search functionality to easily find specific notes

• Implement synchronization across devices for seamless access to notes

Solid design principles are fundamental guidelines for designing software that is maintainable, scalable, and efficient.

• Follow the SOLID principles (Single Responsibility, Open/Closed, Liskov Substitution, Interface Segregation, Dependency Inversion)

• Use design patterns like Factory, Singleton, Observer, etc. to solve common design problems

• Keep code modular, reusable, and easy to understand

• Separate concerns and avoid tight coupling between components

Hashmap is not thread-safe, while ConcurrentHashMap is thread-safe and allows for concurrent access.

• Hashmap is not thread-safe and can lead to race conditions in a multi-threaded environment.

• ConcurrentHashMap is thread-safe and allows for concurrent access by multiple threads without the need for external synchronization.

• ConcurrentHashMap achieves thread-safety by dividing the map into segments, each of which can be locked independently.

• ConcurrentHashMap is preferred for mult...read more

Working code with edge cases is code that has been tested with extreme inputs to ensure it functions correctly.

• Edge cases are inputs that are unlikely to occur but can cause unexpected behavior if not handled properly.

• Examples of edge cases include empty inputs, null values, and inputs at the limits of the data type's range.

• Working code with edge cases should be thoroughly tested to ensure it functions correctly in all scenarios.

CORS stands for Cross-Origin Resource Sharing and is a security feature implemented in web browsers.

• CORS allows web servers to specify which origins are allowed to access their resources.

• It is used to prevent unauthorized access to resources on a different domain.

• CORS is implemented using HTTP headers such as Access-Control-Allow-Origin and Access-Control-Allow-Methods.

• It is important to properly configure CORS to avoid security vulnerabilities.

• For example, if a website hoste...read more

Arrow functions have concise syntax, implicit return, and lexical this binding.

• Shorter syntax than traditional function expressions

• Implicit return of a single expression

• Lexical this binding, avoiding the need for .bind() or self = this

• Example: const double = (num) => num * 2;

• Example: const names = ['Alice', 'Bob', 'Charlie']; const nameLengths = names.map(name => name.length);

System design for android applications involves planning the architecture, components, and interactions of the app.

• Identify the key features and functionalities of the app

• Design the user interface and user experience (UI/UX)

• Choose the appropriate architecture pattern (e.g. MVC, MVP, MVVM)

• Consider scalability, performance, and security

• Implement data storage solutions (e.g. SQLite, Room, Firebase)

• Integrate with external APIs and services

• Test and optimize the app for different d...read more

Reading values from URL using map vs for loop in JavaScript

• Use the window.location.search property to get the query string from the URL

• Map can be used to transform each value in the query string array

• For loop can be used to iterate through each value in the query string array

Develop a take home project involving fetching data from APIs

• Create a project that fetches data from a public API such as weather forecast or news articles

• Use libraries like Axios or Fetch API to make API calls

• Display the fetched data in a user-friendly interface

• Implement error handling for failed API calls

Regulatory audits are inspections conducted by government agencies to ensure compliance with laws and regulations.

• Regulatory audits are conducted by government agencies to ensure compliance with laws and regulations

• They can be scheduled or unscheduled

• They can cover a wide range of areas such as safety, quality, and environmental compliance

• Examples of regulatory audits include FDA inspections for medical device manufacturers and OSHA inspections for workplace safety

• Non-complia...read more

Design a URL shortener system to generate short URLs for long URLs.

• Use a unique identifier for each long URL to generate a short URL.

• Store the mapping of short URL to long URL in a database.

• Implement a redirection mechanism to redirect short URLs to their corresponding long URLs.

The portfolio I managed had an average business of $2 million per year.

• The portfolio I managed had a consistent flow of business throughout the year.

• I was responsible for maintaining and growing the portfolio's business.

• I regularly analyzed the portfolio's performance and made adjustments as needed.

• I worked closely with clients to understand their needs and provide solutions.

• Examples of businesses in my portfolio include XYZ Corporation and ABC Inc.

Intermediate refers to a level of proficiency or knowledge that falls between beginner and advanced.

• Intermediate level typically involves a deeper understanding of concepts and the ability to apply them in practical scenarios.

• Individuals at an intermediate level may have some experience in the field but still have room for growth and learning.

• Examples of intermediate skills include proficiency in a programming language, familiarity with common algorithms, and ability to work ...read more

Various ways to ingest data in BigQuery include batch loading, streaming, and using third-party tools.

• Batch loading: Uploading data in bulk using tools like Cloud Storage or Data Transfer Service.

• Streaming: Sending data in real-time using APIs like Dataflow or Pub/Sub.

• Third-party tools: Using tools like Talend or Informatica for data ingestion.

Implement a hashmap data structure in code.

• Use an array to store key-value pairs

• Implement a hash function to map keys to indices in the array

• Handle collisions using techniques like chaining or open addressing

Design a scalable and fault-tolerant system for a social media platform

• Use microservices architecture to break down the system into smaller, independent services

• Implement load balancing to distribute traffic evenly across servers

• Utilize caching mechanisms to improve performance and reduce database load

• Implement redundancy and failover mechanisms to ensure high availability

• Use monitoring and alerting tools to detect and respond to issues proactively

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

• Architectural design patterns provide guidelines on how to structure and organize software systems.

• Examples include MVC (Model-View-Controller), MVVM (Model-View-ViewModel), and Layered Architecture.

• They help improve the scalability, maintainability, and flexibility of software applications.

Design a parking lot system

• Consider the size and layout of the parking lot

• Include features like ticketing system, payment options, and security measures

• Implement a system to track available parking spaces and manage vehicle entry/exit

Mapping a process involves identifying its steps and creating a visual representation of the flow.

• Identify the process to be mapped

• List the steps involved in the process

• Create a flowchart or diagram to represent the process

• Include decision points and potential outcomes

• Review and refine the process map as needed

Best customer service involves actively listening to customers, addressing their needs promptly, and going above and beyond to exceed their expectations.

• Actively listen to customers to understand their needs and concerns.

• Address customer inquiries and issues promptly and effectively.

• Personalize interactions with customers to make them feel valued and appreciated.

• Go above and beyond by offering additional assistance or solutions to exceed customer expectations.

• Follow up with c...read more

GCD is a low-level API for managing concurrent operations, while Operation Queue is a higher-level API built on top of GCD.

• GCD is a C-based API for managing queues of tasks, while Operation Queue is an Objective-C class that provides a more object-oriented way to manage tasks.

• GCD is more low-level and requires manual management of queues and tasks, while Operation Queue handles many of these details for you.

• Operation Queue allows you to easily cancel, suspend, and resume oper...read more

Implementing infinite scroll for a web application

• Use a front-end framework like React or Angular to handle the scrolling functionality

• Fetch additional data from the server as the user scrolls down the page

• Update the UI with the new data without reloading the entire page

Designing a multiplayer game involves creating a system where multiple players can interact and compete with each other in real-time.

• Consider the game genre and mechanics to determine the type of multiplayer experience (e.g. turn-based, real-time, co-op, competitive).

• Implement networking functionality to allow players to connect to a central server or directly with each other.

• Design a matchmaking system to pair players of similar skill levels or preferences.

• Include features f...read more

Integration testing is testing the interaction between different components or systems to ensure they work together correctly.

• Integration testing verifies that different modules or services work together as expected.

• It focuses on testing the interfaces and communication between components.

• Examples include testing API endpoints, database interactions, and third-party integrations.

I handle pressure by staying organized, prioritizing tasks, and maintaining open communication with my team.

• I prioritize tasks based on deadlines and importance

• I delegate responsibilities to team members to share the workload

• I practice stress-relief techniques such as deep breathing or taking short breaks

• I communicate openly with my team about challenges and seek their input for solutions

Find the longest substring in an array of strings.

• Iterate through each string and compare with all other strings to find common substrings.

• Use a hash table to keep track of the frequency of each substring.

• Return the substring with the highest frequency.

SQL joins are used to combine rows from two or more tables based on a related column between them.

• INNER JOIN: Returns rows when there is at least one match in both tables.

• LEFT JOIN: Returns all rows from the left table and the matched rows from the right table.

• RIGHT JOIN: Returns all rows from the right table and the matched rows from the left table.

• FULL JOIN: Returns rows when there is a match in one of the tables.

• SELF JOIN: Joins a table with itself.

MRP stands for Material Requirements Planning, a system used for managing inventory and production schedules.

• MRP helps businesses determine the materials needed for production based on demand forecasts

• It helps in optimizing inventory levels to reduce costs and meet customer demand

• MRP software often integrates with other systems like ERP for seamless operations

Being on-site is essential for effective collaboration, communication, and access to necessary resources.

• On-site presence allows for real-time collaboration with team members and stakeholders.

• Face-to-face communication can help clarify requirements and expectations more effectively.

• Access to physical resources such as servers or data centers may be necessary for certain tasks.

• Being on-site can also facilitate quicker decision-making and problem-solving.

• Examples: Participating...read more

P value is a measure that helps determine the significance of results in a statistical hypothesis test.

• P value is the probability of obtaining results as extreme as the observed results, assuming the null hypothesis is true.

• A small p value (typically ≤ 0.05) indicates strong evidence against the null hypothesis, leading to its rejection.

• A large p value (> 0.05) suggests weak evidence against the null hypothesis, failing to reject it.

• P value helps in determining whether the re...read more

Use SQL query to find the top 2 highest salaries in a table.

• Use the ORDER BY clause to sort the salaries in descending order.

• Use the LIMIT clause to limit the results to 2.

• Example: SELECT salary FROM employees ORDER BY salary DESC LIMIT 2;

To write power base 10 in logical coding, you can simply use the exponentiation operator or function.

• Use the exponentiation operator '**' in Python to calculate power base 10.

• In JavaScript, you can use the Math.pow() function to calculate power base 10.

• In Java, you can use the Math.pow() function as well to calculate power base 10.

Implement a key-value structure

• Use a hashmap or dictionary data structure to store key-value pairs

• Implement methods to add, retrieve, update, and delete key-value pairs

• Consider handling collisions and implementing a hashing function

• Example: HashMap keyValueMap = new HashMap<>()

The Expectation of a Binomial distribution is equal to the product of the number of trials and the probability of success.

• Expectation = n * p, where n is the number of trials and p is the probability of success

• For example, if you have 10 trials with a success probability of 0.3, the Expectation would be 10 * 0.3 = 3

SAP security refers to the measures taken to protect SAP systems and data from unauthorized access and misuse.

• SAP security involves setting up user roles and authorizations to control access to sensitive data

• It includes implementing encryption, authentication, and audit trails to ensure data integrity

• Regular security assessments and updates are necessary to protect against vulnerabilities

• Examples of SAP security tools include SAP GRC (Governance, Risk, and Compliance) and SAP...read more

System design on web applications involves planning and organizing the architecture, components, and interactions of the system.

• Understand the requirements and constraints of the web application

• Identify the components and modules needed for the system

• Design the architecture including front-end, back-end, and database

• Consider scalability, security, and performance

• Use appropriate technologies and frameworks

• Implement testing and monitoring strategies

Design a platform similar to LinkedIn for professional networking.

• Create user profiles with work experience, education, skills, and endorsements.

• Allow users to connect with others, join groups, and follow companies.

• Include features like job postings, messaging, news feed, and recommendations.

• Implement algorithms for personalized content and job suggestions.

• Ensure data privacy and security measures are in place.

To give space in span, use CSS properties like padding, margin, or line-height.

• Use padding property to add space inside the span element

• Use margin property to add space outside the span element

• Use line-height property to adjust the height of the line containing the span element

Use two heaps to maintain the median in a stream of integers

• Use a max heap to store the smaller half of the numbers and a min heap to store the larger half

• Keep the size of the two heaps balanced or differ by at most 1 to find the median efficiently

Classes are blueprints for objects, while objects are instances of classes.

• Classes define the properties and behaviors of objects

• Objects are instances of classes that can hold data and perform actions

• Classes can be used to create multiple objects with similar characteristics

• Objects can interact with each other through methods and properties

FSSAI stands for Food Safety and Standards Authority of India.

• FSSAI is a government organization responsible for regulating and supervising the food safety standards in India.

• It was established under the Food Safety and Standards Act, 2006.

• FSSAI issues licenses to food businesses based on their compliance with food safety regulations.

• It conducts inspections and monitors food products to ensure they meet safety standards.

• FSSAI also educates and creates awareness among consumer...read more

OOPs concepts refer to Object-Oriented Programming principles that focus on objects, classes, inheritance, encapsulation, and polymorphism.

• Objects: Instances of classes that encapsulate data and behavior

• Classes: Blueprint for creating objects with attributes and methods

• Inheritance: Ability for a class to inherit properties and behavior from another class

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

• Polymorphism: Ability for objects of diff...read more

Self-introduction is a brief introduction of oneself to others.

• Self-introduction should include name, background, and relevant skills.

• It should be concise and to the point.

• It should be tailored to the audience and situation.

• For example, in a job interview, focus on relevant work experience and qualifications.

• In a social setting, include hobbies and interests.

• Practice beforehand to ensure a confident delivery.

I approach problem solving by breaking down the issue, analyzing possible solutions, and implementing the best course of action.

• Identify the problem and gather relevant information

• Brainstorm potential solutions

• Evaluate each solution based on feasibility and effectiveness

• Implement the chosen solution and monitor outcomes

• Adjust the approach if needed

Error handling in React involves creating a component to display error messages and handling errors gracefully.

• Create an ErrorBoundary component to catch errors in child components.

• Use try-catch blocks in async functions to handle errors.

• Display error messages to the user using state or props.

• Use error boundaries to prevent the entire UI from crashing due to a single error.

System design of web apps involves planning the architecture, components, and interactions of a web application.

• Understand the requirements and constraints of the web app

• Identify the key components such as frontend, backend, database, and APIs

• Design the architecture considering scalability, performance, security, and maintainability

• Choose appropriate technologies and frameworks for each component

• Consider factors like load balancing, caching, and data storage

• Plan for monitorin...read more

Merge two sorted arrays and find the median

• Merge the two arrays into one sorted array

• Calculate the median based on the length of the merged array

• Handle cases where the total length is even or odd

Troubleshooting 3P discrepancy involves identifying root causes and implementing solutions to reconcile differences.

• Identify the source of the discrepancy (e.g. data entry error, system glitch)

• Compare data from all 3Ps (people, processes, products) to pinpoint inconsistencies

• Implement corrective actions to resolve the discrepancy and prevent future occurrences

Labour laws are constantly evolving and vary by jurisdiction. It is important to stay up-to-date with changes.

• Labour laws are regulated by federal, state/provincial, and local governments

• Recent updates include changes to minimum wage, overtime pay, and sick leave policies

• COVID-19 has also impacted labour laws, with many jurisdictions implementing new regulations to protect workers

• Employers must ensure compliance with all applicable labour laws to avoid legal issues and penalt...read more

Difference between @Mock and @InjectMock annotations in Java testing

• Use @Mock to create a mock object of a class or interface

• Use @InjectMock to inject the mock object into the class being tested

• Example: @Mock UserService userService; @InjectMock UserController userController;

• Example: Mockito.when(userService.getUserById(1)).thenReturn(new User());

Designing a search engine system involves creating algorithms for indexing, ranking, and retrieving relevant information.

• Consider using inverted index for efficient searching

• Implement ranking algorithms like PageRank or TF-IDF

• Utilize web crawlers to gather and index web pages

• Include features like autocomplete and spell correction for user-friendly experience

super keyword is used to call a method from a parent class in Python inheritance.

• super() returns a temporary object of the superclass, which allows you to call its methods.

• It is used to avoid hard-coding the superclass name in the code.

• super() can also be used to call methods with arguments.

• Example: super().__init__() calls the constructor of the parent class.

The diameter of a tree is the longest path between two nodes in a tree.

• The diameter of a tree can be calculated by finding the longest path between two nodes in the tree.

• It is not necessarily the path between the root and a leaf node.

• The diameter of a tree can be calculated using Depth First Search (DFS) or Breadth First Search (BFS) algorithms.

Design a real-time ad campaign bidding server for efficient ad placement

• Implement a real-time bidding system to allow advertisers to bid on ad placements

• Utilize machine learning algorithms to optimize bidding strategies

• Include features for targeting specific demographics and audiences

• Ensure scalability and low latency for handling high volumes of bid requests

Developed a complex program to automate inventory management for a multinational retail company.

• Implemented a real-time tracking system to monitor inventory levels across multiple warehouses.

• Integrated with suppliers' systems to automatically place orders when stock levels reached a certain threshold.

• Designed a user-friendly interface for employees to easily manage inventory, track shipments, and generate reports.

• Implemented advanced algorithms to optimize inventory allocatio...read more

LC mediums refer to LeetCode mediums, which are medium difficulty coding problems on the LeetCode platform.

• LC mediums are coding problems with medium difficulty level on LeetCode platform.

• Solving 3 LC mediums in 30 minutes requires good problem-solving skills and efficient coding techniques.

• Examples of LC mediums include 'Longest Substring Without Repeating Characters' and 'Container With Most Water'.

Five useful Excel shortcuts for efficient data analysis.

• Ctrl + C: Copy selected cells

• Ctrl + V: Paste copied cells

• Ctrl + Z: Undo previous action

• Ctrl + Shift + Arrow Key: Select entire data range in a direction

• Ctrl + Home: Move to cell A1

Use the 5 and 3lt mugs to measure 4lt.

• Fill the 5lt mug completely

• Pour 3lt from the 5lt mug into the 3lt mug

• Empty the 3lt mug

• Pour the remaining 2lt from the 5lt mug into the 3lt mug

• Fill the 5lt mug again and pour 1lt into the 3lt mug until it's full

• Now the 5lt mug has 4lt of water

Yes, I will sell products as part of my role as a Business Development Associate.

• I will identify potential customers and their needs

• I will pitch products and services to potential customers

• I will negotiate and close deals

• I will maintain relationships with existing customers

• Examples: selling software to businesses, selling advertising space to companies

Use Dutch National Flag algorithm to sort the array in one pass.

• Initialize three pointers low, mid, high at start, iterate through array

• If arr[mid] is 0, swap arr[low] and arr[mid], increment low and mid

• If arr[mid] is 1, increment mid

• If arr[mid] is 2, swap arr[mid] and arr[high], decrement high

• Continue until mid crosses high

Design a calculator app with basic arithmetic operations.

• Include basic arithmetic operations like addition, subtraction, multiplication, and division.

• Design a user-friendly interface with large buttons for numbers and operations.

• Allow users to input numbers using both keypad and touch screen.

• Implement error handling for division by zero and other invalid inputs.

OOPS stands for Object-Oriented Programming System. It is a programming paradigm based on the concept of objects.

• OOPS focuses on creating objects that contain both data and methods to manipulate that data.

• It allows for encapsulation, inheritance, and polymorphism.

• Examples of OOPS languages include Java, C++, and Python.

Automate the calendar using Selenium involves writing scripts to interact with the calendar interface.

• Identify the elements on the calendar interface such as date picker, events, etc.

• Write Selenium scripts to automate tasks like selecting dates, adding events, and navigating through the calendar.

• Use Selenium WebDriver to interact with the calendar elements and perform actions.

• Implement test cases to validate the functionality of the automated calendar.

• Run the Selenium scripts...read more

BPO stands for Business Process Outsourcing, where a company contracts out specific business tasks to a third-party provider.

• BPO involves outsourcing non-core business functions such as customer service, technical support, and data entry.

• Companies often use BPO to reduce costs, improve efficiency, and focus on their core competencies.

• Popular BPO destinations include India, the Philippines, and Eastern Europe.

• Examples of BPO companies include Accenture, Convergys, and Teleperf...read more

Salting is a technique used in cryptography to add random data to passwords before hashing to prevent rainbow table attacks.

• Salting involves adding a random string of characters to a password before hashing it

• The salt value is unique for each password and is stored alongside the hashed password

• Salting prevents attackers from easily cracking passwords using precomputed rainbow tables

• Example: If a password is 'password123', salting it with 'abc123' would result in 'password123a...read more

Spark is a distributed computing framework that processes big data in memory and is known for its speed and ease of use.

• Spark is an open-source, distributed computing system that provides an interface for programming entire clusters with implicit data parallelism and fault tolerance.

• It can run programs up to 100x faster than Hadoop MapReduce in memory, or 10x faster on disk.

• Spark provides high-level APIs in Java, Scala, Python, and R, and an optimized engine that supports gen...read more

DAG implementation involves defining tasks and their dependencies in a directed acyclic graph.

• DAG is a graph where nodes represent tasks and edges represent dependencies between tasks.

• Tasks can only be executed once all their dependencies have been completed.

• Common tools for DAG implementation include Apache Airflow and Luigi.

• Example: Task A must be completed before Task B can start, forming a dependency between them.

The experience you have in the field of service engineering.

• Discuss your previous roles and responsibilities in service engineering.

• Highlight any specific projects or achievements in the field.

• Mention any relevant certifications or training you have received.

• Explain how your experience makes you a strong candidate for the position.

Cost optimization in Big Query involves optimizing query performance, storage usage, and data transfer costs.

• Utilize partitioned tables to reduce query costs by scanning only relevant partitions

• Use clustering to organize data within partitions and improve query performance

• Optimize queries by using efficient SQL syntax and avoiding unnecessary operations

• Leverage caching to reduce repeated query costs

• Monitor and analyze query execution details to identify opportunities for opti...read more

Design a system for a social media platform

• Consider user authentication and authorization

• Include features for posting, liking, commenting, and sharing content

• Implement a notification system for user interactions

• Design a database schema to store user profiles, posts, comments, and relationships

• Scale the system to handle a large number of users and interactions

Designing a Twitter timeline for users to view tweets in chronological order.

• Display tweets in reverse chronological order

• Include tweets from followed users and retweets

• Implement infinite scrolling for continuous feed

• Allow users to like, reply, and retweet tweets

• Include trending topics and suggested users

Project phases are distinct stages in a project's lifecycle, each with specific goals and deliverables.

• Initiation: Define project scope, objectives, and stakeholders.

• Planning: Develop project plan, schedule, and budget.

• Execution: Implement project plan and deliver project deliverables.

• Monitoring and Controlling: Track project progress and make adjustments as needed.

• Closing: Finalize project deliverables and hand off to stakeholders.

• Example: In a software development project, ...read more

Code to reverse a string in an array of strings

• Iterate through each string in the array

• For each string, use a loop to reverse the characters

• Store the reversed string back in the array

Design Walmart search API

• Define search parameters (e.g. product name, category, price range)

• Implement search algorithm (e.g. keyword matching, relevance ranking)

• Integrate with Walmart's product database

• Provide filtering and sorting options

• Ensure scalability and performance

• Include error handling and logging

Balancing technical requirements with project constraints, communication among cross-functional teams, managing stakeholder expectations.

• Balancing technical requirements with project constraints can be challenging as priorities may conflict.

• Communication among cross-functional teams is crucial for successful project delivery.

• Managing stakeholder expectations can be difficult, as different stakeholders may have conflicting needs and priorities.

Yes, I have marketing experience.

• Managed social media accounts for a small business

• Assisted in creating and distributing promotional materials

• Conducted market research to identify target audience

• Collaborated with team to develop marketing strategies

Design a URL shortener system

• Generate a unique short code for each URL

• Store the mapping of short code to original URL in a database

• Redirect users from short URL to original URL

• Consider scalability and performance

• Implement analytics to track usage statistics

P value is a statistical measure that helps determine the significance of results in hypothesis testing.

• P value is the probability of obtaining results as extreme as the observed results, assuming the null hypothesis is true.

• A small P value (typically ≤ 0.05) indicates strong evidence against the null hypothesis, leading to its rejection.

• A large P value (> 0.05) suggests weak evidence against the null hypothesis, leading to its acceptance.

• P value is used in hypothesis testing...read more

SAN is a block-level storage while NAS is a file-level storage.

• SAN is a dedicated network for storage devices while NAS uses existing network infrastructure.

• SAN provides faster access to data and is more suitable for high-performance applications.

• NAS is easier to manage and is more suitable for file sharing and backup.

• SAN requires specialized hardware and software while NAS can be implemented using standard hardware and software.

• Examples of SAN include Fibre Channel and iSCSI...read more

Inheritance in C++ allows a class to inherit properties and behavior from another class.

• Inheritance allows for code reusability by creating a new class based on an existing class.

• Derived class inherits attributes and methods from the base class.

• Types of inheritance include single, multiple, multilevel, and hierarchical.

• Example: class Animal is a base class, class Dog is a derived class inheriting from Animal.

Polyfill for debounce function in JavaScript

• Implement a debounce function that delays invoking a function until after a certain amount of time has passed without it being called again

• Use setTimeout to delay the execution of the function

• Clear the timeout if the function is called again within the specified time frame

• Return a function that can be called to trigger the debounced function

Frontend design involves creating the user interface of a website or application.

• Focus on user experience and usability

• Use responsive design for different screen sizes

• Implement accessibility features for users with disabilities