WhatsApp Inc., a globally renowned instant messaging company, revolutionized digital communication with its user-friendly platform. Acquired by Facebook in 2014, WhatsApp has grown its user base to billions, emphasizing simplicity, security, and reliability.

Landing a role as a Software Engineer at WhatsApp offers an exciting opportunity to contribute to large-scale systems, innovate in messaging technology, and ensure end-to-end encryption. The position calls for proficiency in coding, problem-solving, and scalable system design. Joining WhatsApp means working in a fast-paced environment committed to enhancing global communication.

This guide on Interview Query will navigate you through the interview journey, offering insights into WhatsApp's recruitment process, sample questions, and strategic tips to help you succeed. Let's dive in!

Submitting Your Application

The first step is to submit a compelling application that reflects your technical skills and interest in joining WhatsApp Inc. as a Software Engineer. Whether you were contacted by a WhatsApp recruiter or have taken the initiative yourself, carefully review the job description and tailor your CV according to the prerequisites.

Tailoring your CV may include identifying specific keywords that the hiring manager might use to filter resumes and crafting a targeted cover letter. Furthermore, don’t forget to highlight relevant skills and mention your work experiences.

Recruiter/Hiring Manager Call Screening

If your CV happens to be among the shortlisted few, a recruiter from the WhatsApp Talent Acquisition Team will make contact and verify key details like your experiences and skill level. Behavioral questions may also be a part of the screening process.

In some cases, the WhatsApp Software Engineer hiring manager stays present during the screening round to answer your queries about the role and the company itself. They may also indulge in surface-level technical and behavioral discussions.

The whole recruiter call should take about 30 minutes.

Technical Virtual Interview

Successfully navigating the recruiter round will present you with an invitation for the technical screening round. Technical screening for the WhatsApp Software Engineer role usually is conducted through virtual means, including video conference and screen sharing. Questions in this 1-hour long interview stage may revolve around WhatsApp’s back-end systems, coding challenges, and problem-solving abilities.

Depending on the specific role, take-home assignments regarding coding challenges, system design, and software architecture may be incorporated. Apart from these, your proficiency against data structures, algorithms, and understanding of API integrations may also be assessed during the round.

Onsite Interview Rounds

Followed by a second recruiter call outlining the next stage, you’ll be invited to attend the onsite interview loop. Multiple interview rounds, varying with the role, will be conducted during your day at the WhatsApp office. Your technical prowess, including programming and software system design capabilities, will be evaluated against the finalized candidates throughout these interviews.

If you were assigned take-home exercises, a presentation round may also await you during the onsite interview for the Software Engineer role at WhatsApp.

Quick Tips For WhatsApp Software Engineer Interviews

• Plan to brush up on any technical skills and try as many practice interview questions and mock interviews as possible. A few tips for acing your WhatsApp interview include:

• Understand Scalable Systems: WhatsApp questions often focus on designing and understanding scalable systems to handle millions of users. Brush up on system design principles and large-scale data handling.

• Master Algorithms and Data Structures: WhatsApp places a strong emphasis on coding skills. Prepare by revisiting algorithms and data structures, as you will likely encounter these in coding challenges.
• Be Collaborative: WhatsApp values collaborative problem-solving and team contributions. Practice responding to behavioral questions with answers that reflect your ability to work well in a team environment.

Typically, interviews at Whatsapp Inc. vary by role and team, but commonly Software Engineer interviews follow a fairly standardized process across these question topics.

• How would you set up an A/B test to optimize button color and position for higher click-through rates? A team wants to A/B test changes in a sign-up funnel, such as changing a button from red to blue and/or moving it from the top to the bottom of the page. How would you set up this test?

• Would you suspect anything unusual if an A/B test with 20 variants shows one significant result? Your manager ran an A/B test with 20 different variants and found one significant result. Would you think there was anything fishy about the results?

• Why might the average number of comments per user decrease despite user growth in a new city? A social media company sees a slow decrease in the average number of comments per user from January to March in a new city, despite consistent user growth. What are some reasons for this decrease, and what metrics would you look into?

• What metrics would you use to determine the value of each marketing channel for a B2B company? Given all the different marketing channels and their respective costs at a company selling B2B analytics dashboards, what metrics would you use to determine the value of each marketing channel?

• How would you locate a mouse in a 4x4 grid using the fewest number of scans? You have a 4x4 grid with a mouse trapped in one of the cells. You can "scan" subsets of cells to know if the mouse is within that subset, but not its exact location. How would you figure out where the mouse is using the fewest number of scans?

• Create a function find_bigrams to return a list of all bigrams in a sentence. Write a function called find_bigrams that takes a sentence or paragraph of strings and returns a list of all its bigrams in order. A bigram is a pair of consecutive words.

• Write a query to get the last transaction for each day from a table of bank transactions. Given a table of bank transactions with columns id, transaction_value, and created_at representing the date and time for each transaction, write a query to get the last transaction for each day. The output should include the id of the transaction, datetime of the transaction, and the transaction amount. Order the transactions by datetime.

• Create a function find_change to find the minimum number of coins for a given amount. Write a function find_change to find the minimum number of coins that make up the given amount of change cents. Assume we only have coins of value 1, 5, 10, and 25 cents.

• Design a function to simulate drawing balls from a jar. Write a function to simulate drawing balls from a jar. The colors of the balls are stored in a list named jar, with corresponding counts of the balls stored in the same index in a list called n_balls.

• Create a function calculate_rmse to compute the root mean squared error. Write a function calculate_rmse to calculate the root mean squared error of a regression model. The function should take in two lists, one that represents the predictions y_pred and another with the target values y_true.

• What is the expected number of good ads rated by different types of raters?
• Suppose we have 100 raters each rating one ad independently. What's the expected number of good ads?
• Now suppose we have 1 rater rating 100 ads. What's the expected number of good ads?

• Suppose we have 1 ad, rated as bad. What's the probability the rater was lazy?

• How to simulate coin tosses with a given probability of heads? Write a function that takes the number of tosses and the probability of heads as input and returns a list of randomly generated results ('H' for heads, 'T' for tails) equal in length to the number of tosses.

• How to calculate the sample variance of a list of integers? Write a function that takes a list of integers as input and outputs the sample variance, rounded to 2 decimal places.

• What is the probability of rolling at least one 3 with dice?

• What's the probability of rolling at least one 3 with 2 dice?

• What's the probability of rolling at least one 3 given (N) dice?

• What is the probability of finding an item on Amazon's website given its availability in warehouses? Given that the probability of item X being available at warehouse A is 0.6 and at warehouse B is 0.8, what is the probability that item X would be found on Amazon's website?

• What kind of model did the co-worker develop for loan approval? Your co-worker developed a model that takes customer inputs and returns if a loan should be given or not. What kind of model is this?

• How would you measure the difference between two credit risk models? Given that personal loans are monthly installments, how would you measure the difference between two credit risk models within a timeframe?

• What metrics would you track to measure the success of a new credit risk model? What metrics would you track to measure the success of a new model predicting loan defaults?

• What metrics would you use to track the accuracy and validity of a spam classifier? You have built a V1 of a spam classifier for emails. What metrics would you use to track its accuracy and validity?

• What are the key differences between classification models and regression models? Explain the key differences between classification models and regression models.

• When would you use a bagging algorithm versus a boosting algorithm? You are comparing two machine learning algorithms. When would you use a bagging algorithm versus a boosting algorithm? Provide an example of the tradeoffs between the two.

• What happens when you run logistic regression on perfectly linearly separable data? You are given a dataset of perfectly linearly separable data. What would happen when you run logistic regression?

What is the average salary for a Software Engineer at Whatsapp Inc.?

Q: What is the interview process at WhatsApp like?

A: WhatsApp's interview process typically consists of several stages including a recruiter call, one or more technical phone interviews, and onsite interviews. These stages are designed to evaluate your technical skills, problem-solving abilities, and cultural fit within the company.

Q: What type of technical questions can I expect in the WhatsApp interviews?

A: You can expect questions that focus on data structures, algorithms, system design, and coding problems. Be prepared to solve these problems in real-time and discuss your thought process.

Q: What skills are most important for a Software Engineer at WhatsApp?

A: Key skills include strong programming abilities, a deep understanding of data structures and algorithms, and experience with system design. Familiarity with mobile platforms and messaging systems is a plus.

Q: What is the work environment like at WhatsApp?

A: WhatsApp offers a collaborative and fast-paced work environment. The company values innovation, teamwork, and effective problem-solving. There is a strong emphasis on maintaining a culture that supports personal and professional growth.

Q: How can I prepare for my interview at WhatsApp?

A: Research and practice are crucial. Focus on improving your technical skills through consistent practice, using platforms like Interview Query to solve coding problems and system design questions. Also, familiarize yourself with WhatsApp's products and services to better understand the company's culture and technical challenges.

Embarking on your journey to join Whatsapp Inc. as a Software Engineer is an exciting pathway filled with opportunities to innovate and make a global impact. To ensure you are fully prepared to excel in your interviews, make sure to explore our comprehensive Whatsapp Inc. Interview Guide. This guide covers a wide range of interview questions you might encounter. We've also compiled additional interview guides for roles such as software engineer and data analyst, detailing the interview process at Whatsapp for various positions.

At Interview Query, we are dedicated to equipping you with the knowledge, confidence, and strategies needed to tackle every challenge in your interview process. For a broader preparation scope, check out all our company interview guides. Should you have any questions or need further guidance, we are here to assist.

Best of luck with your interview and your journey towards joining Whatsapp Inc.!