Affirm Software Engineer Interview Questions + Guide in 2024

Affirm is reinventing credit to make it more honest and friendly, empowering consumers to buy now and pay later without hidden fees or compounding interest. As a rapidly growing company, Affirm provides a dynamic environment for software engineers eager to drive growth while developing innovative financial solutions.

As a software engineer at Affirm, you will collaborate with your team to support projects and goals, ensuring transparency about risks and trade-offs while balancing speed and quality in your work to achieve business objectives and maintain system reliability. The ideal candidate is proficient in SQL and Python, comfortable navigating a large code base and code reviews, and possesses strong verbal and written communication skills that foster effective collaboration with their global engineering team.

In this guide, we will provide you with insights into the interview process, possible Affirm software engineer interview questions you might get asked, and preparation tips to help you excel. Let’s get started!

The interview process usually depends on the role and seniority. However, you can expect the following on an Affirm software engineer interview:

Recruiter/Hiring Manager Call Screening

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

Sometimes, the Affirm hiring manager may be present during the screening round to answer your queries about the role and the company itself. The whole recruiter call should take about 30 minutes.

Technical Virtual Interview

Successfully navigating the recruiter round will invite you to the technical screening round. Technical screening for the Affirm Software Engineer role is usually conducted through virtual means, including video conference and screen sharing. Questions in this one-hour interview stage may revolve around leet code coding tasks with runtime constraints.

Prepare to write a program to keep track of items in a cart or similar fundamental problems. Pay attention to proficiency in Python or Kotlin, depending on the requirements specified in the job description.

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(s) at the Affirm office or virtually for remote positions. Your technical prowess, including system design and programming capabilities, will be evaluated against the finalized candidates throughout these interviews.

System design questions for imaginary experiment platforms or similar hypothetical scenarios may sometimes be assigned.

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

1. What are the Z and t-tests, and when should you use each?

Explain what Z and t-tests are, their uses, the differences between them, and the scenarios in which one should be used over the other.

2. What are the drawbacks of the given data layouts, and how would you reformat them for analysis?

Given student test scores in two different layouts, identify the drawbacks of each format. Suggest formatting changes to make the data more useful for analysis and describe common problems in “messy” datasets.

3. What metrics would you use to determine the value of each marketing channel?

Given data on marketing channels and their costs for a company selling B2B analytics dashboards, identify the metrics you would use to evaluate the value of each marketing channel.

4. How would you determine the next partner card using customer spending data?

With access to customer spending data, describe the process you would use to determine the next partner card for a company.

5. How would you investigate if the redesigned email campaign led to the increase in conversion rate?

Given an increase in new-user to customer conversion rate after a redesigned email journey, explain how you would investigate whether the increase was due to the email campaign or other factors.

6. Write a function search_list to check if a target value is in a linked list.

Write a function, search_list, that returns a boolean indicating if the target value is in the linked_list or not. You receive the head of the linked list, which is a dictionary with keys value and next. If the linked list is empty, you’ll receive None.

7. Write a query to find users who placed less than 3 orders or ordered less than $500 worth of product.

Write a query to identify the names of users who placed less than 3 orders or ordered less than $500 worth of product. Use the transactions, users, and products tables.

8. Create a function digit_accumulator to sum every digit in a string representing a floating-point number.

You are given a string that represents some floating-point number. Write a function, digit_accumulator, that returns the sum of every digit in the string.

9. Develop a function to parse the most frequent words used in poems.

You’re hired by a literary newspaper to parse the most frequent words used in poems. Poems are given as a list of strings called sentences. Return a dictionary of the frequency that words are used in the poem, processed as lowercase.

10. Write a function rectangle_overlap to determine if two rectangles overlap.

You are given two rectangles a and b each defined by four ordered pairs denoting their corners on the x, y plane. Write a function rectangle_overlap to determine whether or not they overlap. Return True if so, and False otherwise.

11. How does random forest generate the forest and why use it over logistic regression?

Explain the process of how random forest generates multiple decision trees to form a forest. Discuss the advantages of using random forest over logistic regression, such as handling non-linear data and reducing overfitting.

12. When would you use a bagging algorithm versus a boosting algorithm?

Compare two machine learning algorithms and describe scenarios where bagging is preferred over boosting. Provide examples of the tradeoffs, such as variance reduction in bagging and bias reduction in boosting.

13. How would you evaluate and compare two credit risk models for personal loans?

1. Identify the type of model developed by the co-worker for loan approval.
2. Describe how to measure the difference between two credit risk models over a timeframe, considering monthly installment payments.
3. List the metrics to track for measuring the success of the new model, such as accuracy, precision, recall, and AUC-ROC.

14. What’s the difference between Lasso and Ridge Regression?

Explain the key differences between Lasso and Ridge Regression, focusing on their regularization techniques and how they handle feature selection and multicollinearity.

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

Describe the fundamental differences between classification and regression models, including their objectives, output types, and common use cases.

16. How would you design a function to detect anomalies in univariate and bivariate datasets?

If given a univariate dataset, how would you design a function to detect anomalies? What if the data is bivariate?

17. What is the expected churn rate in March for customers who bought the product since January 1st?

You noticed that 10% of customers who bought subscriptions in January 2020 canceled before February 1st. Assuming uniform new customer acquisition and a 20% month-over-month decrease in churn, what is the expected churn rate in March for all customers who bought the product since January 1st?

18. How would you explain a p-value to a non-technical person?

How would you explain what a p-value is to someone who is not technical?

You should 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 Affirm data engineer interview include:

• Understand Affirm’s Products and Culture: Familiarize yourself with Affirm’s offerings, including its mission to reinvent credit. Knowing how Affirm’s products are structured and their impact on consumers will help you frame your answers.
• Technical Preparedness: Brush up on fundamental coding skills, especially problem-solving using data structures and algorithms. Practice coding on platforms like Interview Query to enhance your preparedness.
• Engage and Clarify: Don’t hesitate to ask clarifying questions during the interviews. Engaging and showing curiosity about the problem at hand can demonstrate your problem-solving approach and communication skills.

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

What is the company culture like at Affirm?

Affirm is known for its positive and collaborative company culture. Emphasis is placed on innovation, transparency, and continuous improvement. Employees are encouraged to take ownership, communicate effectively, and support each other.

What are some of the benefits of working at Affirm?

Affirm offers competitive benefits including full healthcare coverage for you and your dependents, flexible spending wallets for technology, food, lifestyle needs, and family forming expenses, as well as competitive vacation and holiday schedules. They also provide an employee stock purchase plan (ESPP).

The interview experiences for the Software Engineer position at Affirm, Inc. span the full spectrum from extremely positive to negative. While some applicants appreciated the friendly, thorough, and informative engagement from their interviewers, others experienced poor communication, repetitive cancellations, and a lack of feedback post-interview. Technical assessments seemed to vary, with some finding them straightforward while others struggled with disengaged interviewers and insufficient guidance.

If you’re aiming to dive deep into Affirm’s interview process and want to prepare thoroughly, check out our comprehensive Affirm Interview Guide. We’ve compiled essential interview questions and detailed role-specific insights, from software engineering to data analysis, to help you succeed in your application.

Good luck with your interview!