Stripe Interview Questions

Stripe, Inc. stands at the forefront of the digital payment revolution, offering cutting-edge solutions for online businesses. As a pioneer in the e-commerce realm, the company delivers a comprehensive set of tools designed for seamless transactions, recurring billing, and modern e-commerce challenges.

As the industry landscape continues to evolve, Stripe remains committed to constant innovation. They’re seeking tech talents to further their mission, from refining their core payment platform to developing advanced fraud detection systems and expanding payment options for a diverse global market.

In this guide, we’ll touch on Stripe’s interview process and highlight practice questions for topics frequently covered in the company’s interviews.

Stripe’s interview process is tailored to assess a candidate’s technical experience, problem-solving skills, and alignment with company values. This comprehensive process includes:

1. Initial Coding Challenge: Unlike more conventional technical assessments, Stripe’s coding test looks at more than whether candidates can find a solution. Instead, this stage focuses on how candidates communicate their thought processes and interact with the problem.
2. Behavioral Assessment: A major factor in the company’s hiring process is understanding the ‘why’ behind a candidate’s application. Before diving deeper into technical evaluations, candidates will be asked about previous experiences and motivations for joining Stripe.
3. Debugging Rounds: In this round, candidates are presented with a complex piece of code, putting their debugging skills to the test. Whether it’s a vast repository with a singular bug for software engineers or SQL challenges for data analysts, the goal is to assess a candidate’s ability to navigate and fix complex issues.
4. Integration Challenge: This is a multi-faceted technical round where candidates are tested on REST clients, JSON Parsing, and more. Like other technical rounds in this process, candidates are evaluated on both their actual solutions and how they utilized problem-solving skills in their approach.
5. Product Design: This round evaluates a candidate’s understanding of Stripe’s product suite. Expect to discuss design decisions, trade-offs, and the rationale behind them.

While a large organization, Stripe’s interview experiences are uniquely tailored to the role, team, and individual. While the process might vary across teams and roles, the core objective remains consistent: to identify candidates who resonate with Stripe’s ethos and vision.

Stripe uses a combination of MySQL and MongoDB in their production databases. Knowing how to query and efficiently interact with relational databases is vital to securing a role. Here are some of the SQL questions that you might encounter with Stripe.

1. How would you identify unauthorized bank withdrawals from a table?

Given a bank transactions table with columns for user_id, transaction time (created_at), and withdrawal value (transaction_value), write a query to find all the user IDs, in ascending order, who made withdrawals with exactly a 10-second gap between them.

Note: Only consider withdrawals from the ATM, which are represented by a positive transaction_value.

2. Find the last bank transaction for each day.

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 fetch the last transaction for each day.

The output should include the transaction id, datetime (created_at), and amount (transaction_value), ordered by datetime.

3. What is the three-day rolling average for deposits by day?

Given a table of bank transactions with columns user_id, transaction_value (positive and negative values indicate a deposit and withdrawal, respectively), and created_at (the date and time of each transaction), find the total three-day rolling average for deposits by day. The date in the output should be formatted as ‘%Y-%m-%d’.

For more help with SQL, try the SQL learning path and the full list of SQL questions and solutions in our interview questions database.

As a BaaS (Backend as a Service) company specializing in delivering payment solutions to other software platforms, Stripe needs algorithm experts to ensure secure and efficient processes in production code.

4. How would you organize a list of strings in alphabetical and numerical order?

Given an array of strings arr where each string follows the format: <letters><number> (e.g., “a1”, “b32”, or “caba522”), create a function that sorts the list of strings first by alphabetical order, and then numerically in descending order.

Note: The letters will always be in lowercase and have a length of at least 1.

To solve this problem, consider how you can split the string into its letter and number components. Once separated, think about leveraging built-in sorting methods, possibly with a custom sorting function, to achieve the desired order.

5. Format an array so that each line has the exact same number of characters.

Given an array of words and a max_width parameter, create a function justify to format the text so that each line has exactly max_width characters. When necessary, pad the lines with extra spaces to ensure that each line meets the max_width requirement.

Distribute the extra spaces between words as evenly as possible. If the number of spaces on a line doesn’t divide evenly between words, the excess spaces should be placed on the right-hand side of the line.

To start, determine how many words can fit on a line without exceeding the max_width. Once you’ve placed the words, calculate the number of spaces needed to reach the max_width. How can you distribute these spaces evenly between the words?

6. How would you remove stop words from a string?

Given a list of stop words, create a function stopwords_stripped that takes in a string and returns a new string that has been stripped of all the stop words. The new string should be entirely in lowercase.

To solve this problem, consider how you can check each word against the list of stop words.

To practice coding interview questions, check out the Python learning path or the full list of Algorithms questions in our database.

Case studies are an integral part of Stripe’s interview process and are often asked in one of the very last stages. Understanding how to interact with real-world processes outside of algorithmic, sandboxed solutions is essential for any data professional.

7. Evaluate whether hiring a customer success manager or offering a free trial would increase user acquisition of a new product.

Let’s say you’re in charge of Square’s small business division.

The CEO wants to hire a customer success manager to help manage a new software product. Another executive thinks that instituting a free trial would work better instead.

What would be your recommendation for hiring a customer success manager versus using a free trial to get new or existing customers to use the product? Describe some of the trade-offs in this scenario.

8. What are some of the important factors to consider when designing an ETL pipeline?

You’re tasked with importing payment data into your company’s internal data warehouse. Your primary data source is Stripe, a popular payment processing platform. How would you build an ETL pipeline to get Stripe payment data into the database so analysts can build revenue dashboards and run analytics?

Start by outlining the structure of Stripe’s data and the available API endpoints. Stripe’s API can be used to extract the necessary payment data. What would the next steps be?

After figuring out your basic solution, let’s consider some more advanced cases. How would you handle data updates or modifications in Stripe? Can you design the pipeline to be fault-tolerant and scalable? Consider potential issues like API rate limits, data discrepancies, and data security during the transfer process. How would you monitor and maintain the pipeline to ensure continuous and accurate data flow?

9. How would you determine if an email marketing campaign would help boost revenue?

Let’s say that you’re a data scientist working on the marketing team of a B2B SAAS business.

We’re nearing the end of the quarter and are missing revenue expectations by 10%. An executive wants the email marketing person to send out a huge email blast to your entire customer list, asking them to buy more products.

Is this a good idea? Why or why not? If not, describe some alternative solutions that may be more effective.

To practice for case studies, we recommend using the product metrics and data analytics learning paths.

Practice for the Stripe interview with these recently asked interview questions.