Top 22 Pinterest Software Engineer Interview Questions + Guide in 2024

As a candidate for Pinterest’s software engineering interview, you must be wondering about the process and the questions that may prove challenging.

In this article, we’ll discuss the interview process, a few medium-to-hard Pinterest software engineer interview questions, and a preparation strategy you can embrace.

Understanding the interview process is just as critical as preparing the recurring questions asked in the Pinterest software engineer interviews. We’ll discuss the typical interview process for the role in this section.

1. Recruiter Call

Your interview process is expected to begin with a call from a Pinterest recruiter—possibly a third-party organization. This initial conversation is an opportunity for you to gain deeper insights into the role and the interview process.

Take advantage of this time to ask any questions you may have, as the conversation is as much about Pinterest assessing your fit as it is about you understanding the company.

2. Video Screening

Following the recruiter call, you will engage in a 45 to 60-minute video screening with a Pinterest Engineer. This session often involves the use of collaborative coding tools, including CoderPad.

The video screening is designed to evaluate your general programming skills, specialized knowledge (such as SQL and data structure), and overall interests. The format typically includes introductions, coding questions, and an opportunity for you to pose questions about the role or Pinterest itself.

3. Onsite Interview

The final step is the onsite interview, where you will visit the Pinterest office for a series of five interviews. These interviews are distributed across various types:

• Data Structures/Algorithms: Assessing your problem-solving skills and algorithmic knowledge.
• Architecture/Systems Design: Evaluating your ability to design scalable and efficient systems.
• Domain Specific: Tailored to roles requiring specialized knowledge.
• Lunch Interview/Hiring Manager/Values: A more informal session covering cultural fit, team dynamics, and alignment with Pinterest’s values.

Depending on the location and the circumstances, the interview process may vary and embrace a remote-exclusive approach. In those cases, question types may also vary and include more practical problems than onsite interviews.

Pinterest Software Engineer interviews usually revolve around data structure, database, SQL queries, algorithms, coding, debugging, and a few behavioral questions. Aside from those, you may also encounter counter questions to your answers that your interviewer may find inquirable.

Moreover, system design and improvement questions related to Pinterest may also be asked to offer you an opportunity to explain how you would perceive a UI issue, such as redesigning the home feed.

From the experience of the candidates, both accepted or otherwise, the overall interview process at Pinterest belongs to a neutral to positive territory. The interviewers are expected to be friendly and outgoing. However, you’ll need to go through multiple rounds of coding and behavioral rounds before being selected.

Let’s discuss a couple of the questions that usually find their way to the Pinterest interview panels.

1. Tell me a time when your colleagues did not agree with your approach. What did you do to bring them into the conversation and address their concerns?

The interviewer assesses your ability to handle disagreements and conflicts within a team. They want to know if you’ll be able to effectively communicate and collaborate with different teams within Pinterest.

How to Answer

Share a specific example where your approach differed from your colleagues’, highlighting your communication and problem-solving skills. Emphasize how you facilitated an open dialogue and incorporated their perspectives.

Example

“In a previous project, there was disagreement about the technology stack to use. I organized a team meeting to discuss the pros and cons of each approach. We collaboratively evaluated the options, addressed concerns, and eventually decided on a hybrid solution that combined the strengths of both preferences. This ensured everyone felt heard and led to a successful project.”

2. How do you prioritize multiple deadlines? Additionally, how do you stay organized when you have multiple deadlines?

This question assesses your time management and organizational skills. The interviewer wants to know how you handle multiple tasks with different deadlines.

How to Answer

Explain your approach to prioritization, such as using a task management system, setting clear priorities, and breaking down larger tasks into smaller, manageable steps. Mention common tools that you use.

Example

“I prioritize deadlines by assessing the urgency and importance of each task. I use a task management tool like Trello to create a visual board, categorize tasks, and set deadlines. This helps me stay organized and ensures that I address high-priority tasks first.”

3. How do you prioritize and manage your time when working on multiple tasks or projects?

The question is aimed to assess your organizational skills, time management, and ability to handle multiple responsibilities.

How to Answer

Set off by mentioning the importance of prioritization based on urgency and impact.

If possible, discuss your use of tools (e.g., task management software) and strategies for effective time management.

Example

“I prioritize tasks based on their urgency and impact. I often use task management tools to track deadlines and employ the Eisenhower matrix to categorize tasks. Regularly reassessing priorities ensures that critical tasks are addressed promptly.”

4. Describe how you would coordinate with cross-functional teams, including product managers and designers, to ensure the successful rollout of a new Pinterest feature.

Your collaborative, leadership, and communicative skills will be put to the test through this question. The interviewer wants to know how you work with cross-functional teams to deliver successful features.

How to Answer

Stress the importance of maintaining a collaborative and transparent process throughout the development lifecycle. Explain your approach to collaboration, including effective communication, understanding requirements, and incorporating feedback.

Example

“Communication is key when collaborating with cross-functional teams. I’ll start by holding regular meetings to align on the feature’s goals. I will make sure that product managers and designers understand the technical constraints and possibilities.

I would establish regular feedback loops through using tools like project management platforms. Throughout development, open channels of communication and a shared project documentation system would ensure everyone is on the same page. I’d also conduct regular review sessions to incorporate feedback and iterate on the feature.”

5. Pinterest deals with a vast amount of user-generated content. How would you ensure the privacy and security of user data on the platform?

The primary objective behind this question is to assess how important you understand the privacy and security considerations in handling large amounts of user-generated content on a platform like Pinterest.

How to Answer

Discuss strategies for secure data storage, access controls, encryption, and compliance with data protection regulations. Emphasize the importance of an increasingly robust and dynamic security infrastructure.

Example

“Ensuring privacy and security involves implementing strong encryption protocols for both data in transit and at rest. Access controls and authentication mechanisms should be in place to restrict data access to authorized personnel. Regular security audits and compliance with industry standards, such as GDPR, are crucial. Implementing features like two-factor authentication can further enhance user account security.”

6. Write a function to get a sample from a standard normal distribution.

The interviewer is testing your understanding of probability distributions and your ability to generate a random sample from a standard normal distribution.

How to Answer

Use libraries or the built-in functions of a programming language to generate a random number from a normal distribution.

Example

import numpy as np

def get_sample_from_normal_distribution():

return np.random.normal()

# Usage:

sample = get_sample_from_normal_distribution()

print(sample)

7. You are designing an ETL pipeline for a model that uses videos as input. How would you collect and aggregate data for multimedia information, specifically when it’s unstructured data from videos?

The interviewer is assessing your understanding of Extract, Transform, and Load (ETL) processes and your approach towards unstructured data, such as videos.

How to Answer

Discuss the importance of data extraction, transformation, and loading in the context of machine learning models. Mention the use of tools and emphasize the need for feature engineering.

Example

“To design an ETL pipeline for video input, I would initially use a tool like Apache Spark to handle the distributed processing of large video datasets. The extraction phase would involve parsing video metadata, extracting frames, and using pre-trained models to identify key features.

Transformation would include feature engineering to convert video frames into structured data, and loading would involve storing the processed data in a suitable format like Parquet or Avro. This structured data can then be fed into the machine learning model for training or inference.”

8. Write a SQL query to select the 2nd highest salary in the engineering department.

Note: If more than one person shares the highest salary, the query should select the next highest salary.

Example:

Input:

employees table

Column	Type
id	INTEGER
first_name	VARCHAR
last_name	VARCHAR
salary	INTEGER
department_id	INTEGER

departments table

Column	Type
id	INTEGER
name	VARCHAR

Output:

Column	Type
salary	INTEGER

The problem assesses your SQL skills and evaluates your capability to write a query that involves filtering and ordering data.

How to Answer

Use the SELECT, FROM, WHERE, and ORDER BY clauses to retrieve the desired information. Use the LIMIT clause to get the second-highest salary.

Example

• Identify the department_id for ‘Engineering’ from the departments table.
• Use a subquery to find the maximum salary in the engineering department.
• Use another subquery to find the maximum salary that is less than the maximum salary found in step 2. This ensures that you get the second-highest salary.
• Finally, select the maximum salary obtained from the subquery as the result.
• This query works by finding the maximum salary in the engineering department that is less than the overall maximum salary in the same department, effectively giving you the second-highest salary.

SQL Code:

SELECT MAX(salary) AS second_highest_salary

FROM employees

WHERE department_id = (SELECT id FROM departments WHERE name = ‘engineering’)

AND salary < (SELECT MAX(salary) FROM employees WHERE department_id = (SELECT id FROM departments WHERE name = ‘engineering’));

9. What are the Z and t tests? What are they used for? What is the difference between them? When should use one over the other?

The interviewer is hoping to understand the concepts of Z and t tests, their applications, differences, and when to use one over the other.

How to Answer

Briefly define Z and t tests, mention their common applications, highlight the main difference (sample size), and discuss when to choose each based on the sample size.

Example

“The Z test is used when the sample size is large (typically > 30), and the population standard deviation is known. The t test, on the other hand, is suitable for smaller sample sizes when the population standard deviation is unknown.

If the sample size is large, both tests yield similar results. However, for smaller samples, the t test provides more accurate results. Choose the Z test for larger sample sizes and when the population standard deviation is known; otherwise, opt for the t test.”

10. Amy and Brad take turns rolling a fair six-sided die. Whoever rolls a “6” first wins the game. Amy starts by rolling first. What’s the probability that Amy wins?

This question assesses your ability to recognize, understand, and solve a fairly easy probability problem.

How to Answer

Recognize that Amy wins if she rolls a “6” before Brad, and apply the probability formula for winning in one turn.

Example

Since Amy rolls first, the probability of her winning on her first turn is ¹⁄₆. If she doesn’t win on the first turn, the game restarts with Brad rolling first. The overall probability of Amy winning is the sum of the probabilities of winning on her first turn, second turn, third turn, and so on. The formula for this infinite geometric series is P(Amy wins) = ¹⁄₆ + (⁵⁄₆) * (¹⁄₆) + (⁵⁄₆)^2 * (¹⁄₆) + … = ¹⁄₆ * (1 / (1 - ⁵⁄₆)) = ¹⁄₆ * 6 = 1.

11. Let’s say you’re working on keyword bidding optimization. You’re given a dataset with two columns. One column contains the keywords that are being bid against, and the other column contains the price that’s being paid for those keywords. Given this dataset, how would you build a model to bid on a new unseen keyword?

The interviewer is assessing your ability to design a model for keyword bidding optimization based on a given dataset.

How to Answer

Acknowledge the need to predict an optimal bid for a new keyword and identify relevant features, such as keyword popularity, historical performance, and current market trends.

Choose a suitable machine learning model for regression tasks. Use the given dataset to train the model, ensuring proper validation.

Example

“I would approach this problem by selecting features such as keyword popularity, historical performance, and current market trends. I’d opt for a linear regression model due to its simplicity and interpretability. After training the model on the provided dataset, I’d evaluate its performance using metrics like Mean Squared Error. Continuous monitoring and periodic updates would be essential for maintaining effectiveness in a dynamic bidding environment.”

12. How would you explain the concept of linear regression to three different audiences: a child, a first-year college student, and a seasoned mathematician? Ensure your explanations are tailored to the understanding level of each audience.

Your answer to this question will demonstrate your ability to communicate complex concepts to audiences with varying levels of understanding.

How to Answer

Explain how you would approach the problem according to the age and level of understanding for each audience. Offer a few examples that may help your interviewer visualize your point of view.

Example

“For a child: Linear regression is like drawing a straight line through points on a graph to guess where the next point might be.

For a first-year college student: Linear regression is a statistical method used to model the relationship between a dependent variable and one or more independent variables by fitting a linear equation.

For a seasoned mathematician: Linear regression is a method to model the relationship between variables by finding the line that minimizes the sum of squared differences between observed and predicted values.”

13. What is an unbiased estimator, and can you provide an example for a layman to understand?

You’re required to convey your understanding of an unbiased estimator and its behavior when estimating a correct result.

How to Answer

You need to briefly explain that an unbiased estimator is like taking an average of multiple guesses, where some may be too high and others too low, but the average tends to be accurate.

Example

“ An unbiased estimator is a statistical estimator that, on average, accurately predicts the true value of a parameter without systematic errors or biases. In simpler terms, it gives accurate predictions without consistently overestimating or underestimating.

An example of an unbiased estimator is the sample mean when estimating the population mean. If you repeatedly take random samples from a population and calculate the mean each time, the average of those sample means will be very close to the true population mean.”

14. Explain the difference between a linked list and an array. When would you choose one over the other?

As Pinterest is a platform reliant heavily on DS/Algo, the interviewer would assess your understanding of fundamental data structures and your ability to choose the right one for a given scenario with this question.

How to Answer

Mention what an array is and its limitations. Also, describe what a linked list consists of and how it’s preferable when dynamic sizing is critical.

Example

“An array is a contiguous memory block, allowing for constant-time access but with a fixed size. On the other hand, a linked list consists of nodes with pointers to the next node, providing dynamic size but slower access.

Arrays are suitable for scenarios where constant-time access is crucial, such as in scenarios requiring frequent random access to elements. On the other hand, linked lists are preferable when dynamic size and efficient insertions/deletions are more critical, as they don’t require contiguous memory allocation.”

15. Explain the concept of test-driven development (TDD)

Understanding software development methodologies is critical for Pinterest interviews. This question particularly evaluates the extent of knowledge of your TDD concept.

How to Answer

Explain what Test-Driven Development (TDD) is and how it’s involved in writing tests. Emphasize the cycle of writing tests and refactoring if needed. Do consider mentioning the steps of the cycle.

Example

“Test-driven development is a methodology where tests are written before the actual code. The development process follows a cycle: write a failing test, write the minimum code to pass the test, refactor if necessary, and repeat. This approach helps ensure code correctness and maintainability.”

16. Describe the use of a hash table in optimizing Pinterest’s search functionality.

Exploring the application of hash tables in optimizing search functionality, your answer would allow your interviewer to assess your understanding of data retrieval based on keys.

How to Answer

Explain how hash tables enable faster data lookup through the means of mapping and storing. Link the process with the cornerstones of Pinterest, such as pins and boards.

Example

“Hash tables work by converting keys into hash codes, mapping them to indices, and storing values at those locations, resulting in constant-time average-case complexity for search operations.

In Pinterest’s search functionality, a hash table could be employed to index keywords, mapping them to relevant pins or boards. This ensures swift retrieval of content associated with specific search queries.”

17. Explain the differences between a stack and a queue. Provide examples of situations where each would be more suitable in a Pinterest-related scenario.

Data structure and algo, being fundamental for Pinterest, the interviewer is expected to assess your understanding of fundamental data structures (stacks and queues) and their applicability.

How to Answer

Consider differentiating between stacks (Last In, First Out) and queues (First In, First Out). Explain scenarios where their characteristics align with specific use cases in a Pinterest-related context.

Example

“A stack could be used to track user navigation history. It could be used to ensure the most recently visited pages are easily accessible. In contrast, a queue might be suitable for managing notifications and processing them in the order they arrive.”

18. Describe the difference between unit testing and integration testing.

The interviewer aims to assess your understanding of testing methodologies. They want to know if you can differentiate between unit testing and integration testing.

How to Answer

Begin with what unit testing and integration testing are, and make your way through with appropriate examples of the same.

Example

“Unit testing involves testing individual functions or methods to ensure they work as expected. Integration testing, on the other hand, verifies that these functions collaborate seamlessly when integrated into the overall system.

An example of unit testing would be testing a specific function that calculates the total cost of items in a shopping cart, while integration testing would ensure that this function interacts correctly with other components, such as the payment processing module.”

19. How would you enhance the user experience on Pinterest without making significant changes to the existing UI?

Your practicality and creative ability to improve the user experience within the constraints imposed by the platforms will be tested through the question. However, the interviewer may also like to know how you perceive user experience as a software engineer.

How to Answer

You may propose small, impactful changes that can enhance user engagement without a major overhaul of the UI. Moreover, you should emphasize the importance of user feedback and data analysis in driving improvements.

Example

“I would focus on refining the recommendation algorithm to provide more personalized content based on user preferences. Introducing subtle animations or micro-interactions can also create a more engaging and enjoyable experience without restructuring the existing UI. Regularly collecting user feedback and analyzing usage patterns will be crucial to identify areas for improvement.”

20. Discuss the role of machine learning algorithms in tailoring content suggestions based on a user’s browsing history and preferences.

If applicable, the interviewer wants to comprehend your understanding of how machine learning contributes to personalizing content recommendations.

How to Answer

They are looking for insights into the application of algorithms in leveraging user data for a more personalized experience. Highlight the importance of machine learning in analyzing user behavior, understanding preferences, and predicting relevant content on Pinterest. Mention the use of recommendation algorithms, collaborative filtering, and possibly deep learning techniques.

Example

“Machine learning plays a pivotal role in tailoring content suggestions on Pinterest. Algorithms analyze a user’s past interactions, such as pins, clicks, and searches, to understand preferences. Collaborative filtering is used to recommend content based on similar user behaviors. Deep learning models can capture intricate patterns, enhancing the accuracy of personalized recommendations.”

21. Given two strings, string1 and string2, write a function is_subsequence to find out if string1 is a subsequence of string2.

This question is likely asked in a Pinterest software engineer interview to assess your ability to work with strings and demonstrate problem-solving skills with basic algorithmic concepts. Checking if one string is a subsequence of another involves understanding iteration, condition checking, and string manipulation, which are fundamental skills for a software engineer.

How to Answer

Notice that in the subsequence problem set, one string in this problem will need to be traversed to check for the values of the other string. In this case, it is string2.

The idea to solve this should then be simple. We traverse both strings from one side to the other side going from leftmost to rightmost. If we find a matching character, we move ahead in both strings. Otherwise, we move ahead only in string2.

Example

“I would first consider the goal of determining whether one string is a subsequence of another. The approach I would take involves iterating through both strings simultaneously, where I would compare the characters of the first string with the second. If they match, I would move to the next character in the first string, otherwise, I would continue to iterate through the second string. This method should efficiently determine if all characters of the first string appear in order within the second. By the end of the iteration, if I’ve matched all characters, it confirms that the first string is indeed a subsequence.”

22. Given two lists of release dates, return the list with more dates past a certain input variable date D.

This question might be asked to assess your ability to handle lists and perform comparison operations efficiently. It tests your knowledge of data structures, particularly lists, and how well you can manipulate and filter them based on given conditions.

How to Answer

We want to get the list that has more dates past date D. Convert every date string to a date time object so that we can compare.

Example

“I would start by converting the input date to a datetime object for easy comparison with the dates in both lists. I could then iterate through each list, counting how many dates are past the given date. By comparing these counts, I could determine which list has more dates beyond the input date. Finally, I would return the list with the higher count. This approach should handle any discrepancies in list lengths or date order, ensuring that I get the correct result efficiently.”

With the questions out of the way, let’s discuss how you can successfully prepare for the software engineering role at Pinterest.

Understand the Interview Process

Familiarize yourself with the three main steps: recruiter call, video screening, and onsite interview. Note the emphasis on both Pinterest interviewing you and your opportunity to interview Pinterest during the Recruiter Call.

Technical Preparation

Brush up on data structures and algorithms, as they are frequently assessed. Practice coding problems related to Pinterest’s technical requirements. Understand system design principles, especially for scalability and efficiency.

Boost your technical knowledge of data structures and databases by solving coding interview questions about SQL and Python. Feel free to move up the difficulty ladder as per your experience.

Behavioral Preparation

Prepare for behavioral questions related to your past experiences and problem-solving approach. Emphasize collaboration, communication, and alignment with Pinterest’s values during the Lunch Interview or with the Hiring Manager.

Stay Updated

Keep abreast of industry trends, especially those relevant to Pinterest’s technology stack. Research Pinterest’s engineering practices and innovations to demonstrate your genuine interest.

Mock Interviews

Conduct mock interviews to simulate the Pinterest interview environment. Seek feedback to refine your problem-solving and communication skills.

If you are not feeling confident yet, take a mock interview to evaluate your preparedness. Aside from boosting your confidence, it would help you refine your answers more accurately.

Cultural Fit

Understand Pinterest’s company culture and values. Showcase your alignment with these values during the onsite interviews.

Reflect on Past Work

Be prepared to discuss your past projects and experiences, emphasizing challenges and solutions. It’s recommended to bring your open-source projects along.

How much do software engineers at Pinterest make in a year?

A Pinterest software engineer makes around $155K on average, but it can be pushed to $220k depending on the experience and knowledge. The total compensation, including stocks and healthcare, may well exceed the $600k mark for experienced engineers.

Take a look at the Software Engineer Salary spectrum to feel good about applying to Pinterest and encourage yourself to prepare better.

Where can I read more discussion posts on the Pinterest Software Engineer role here on Interview Query?

You may find the answer to your query in the discussion board for Pinterest. If willing, don’t hesitate to share your experience with others. Also, make sure to use the search bar to find what you need.

Are there job postings for Pinterest Software Engineer roles on Interview Query

Yes, you’ll find all the relevant job openings on our Pinterest job board. Directly apply from there or consider going through other similar roles that may enrich your experience and fulfill your career goals.

If you want to read more about Pinterest and the other roles we have covered, please head on over to our main Pinterest Interview Guide. In it, we extensively discuss the perks of working at Pinterest and the relevant interview questions they ask for positions such as Data Engineer, Analyst, Scientist, and Machine Learning Engineer.

As a Software Engineering candidate at Pinterest, you need to demonstrate both technical and behavioral proficiency, so feel free to reach out to us if you need additional help or have any questions regarding our services.

We’re looking forward to you acing that interview!