Klaviyo Software Engineer Interview Questions + Guide in 2024

Klaviyo is a leading real-time data analytics platform that empowers creators to make first-party data accessible and actionable. Known for its innovative technology that nurtures personalized experiences in e-commerce and beyond, Klaviyo is a fast-growing company aiming to reach new heights.

As a Software Engineer at Klaviyo, you will be at the forefront of building advanced systems using technologies such as Python, Django, AWS, and more. You will take on a variety of technical challenges, from optimizing code to designing scalable systems, all while contributing to a dynamic, collaborative, and highly impactful team.

Thinking of joining Klaviyo? Dive into this comprehensive guide by Interview Query to navigate through their interview process, commonly asked Klaviyo software engineer interview questions, and valuable tips. Let’s get started!

The interview process usually depends on the role and seniority; however, you can expect the following on a Klaviyo software engineer interview:

Recruiter/Hiring Manager Call Screening

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

The screening questions are standard for software engineering roles, so be prepared to speak on previous projects and what you are looking for in your next role. Sometimes, the 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 Screening

Successfully navigating the recruiter round will invite you to the technical screening round. This involves a take-home technical problem, typically using a platform like CodeSignal, and consists of finding and fixing bugs in existing pieces of code. This technical screening is more “real-world” focused than the leetcode-style, revolving around REST APIs, Python, SQL, and similar technologies.

Pair programming sessions are also incorporated, where you will collaborate with Klaviyo engineers to work through the technical problem. Be prepared for discussions on practical web development issues and how to optimize existing solutions.

Onsite Interview Rounds

After the technical screening, the next stage comprises the onsite interview loops, which are often virtual. Multiple interview rounds are conducted, focusing on:

• In-depth technical challenges
• System design questions
• Behavioral interviews
• Code reviews

You might have technical interviews with lead engineers or directors. These rounds are thorough and involve solving practical problems, ensuring candidates are evaluated on both their coding proficiency and problem-solving skills. Interviewers may also discuss your previous project experiences in detail and ask you to optimize given code snippets.

For comprehensive practice and preparation, check out Interview Query.

Typically, interviews at Klaviyo vary by role and team, but common software engineer interviews follow a fairly standardized process across these question topics.

1. Write a query to get the average order value by gender.

Given three tables representing customer transactions and customer attributes, write a query to get the average order value by gender. Round the answer to two decimal places.

2. Write a function combinational_dice_rolls to dump all possible combinations of dice rolls.

Given n dice each with m faces, write a function combinational_dice_rolls to dump all possible combinations of dice rolls. Bonus: Can you do it recursively?

3. Estimate the annual cost of overlapping computing jobs.

Write a function to simulate the problem of two computing jobs overlapping and causing downtime. Output an estimated annual cost based on 365 days. Bonus: How would you solve this using probability?

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

Create a function to generate a sample from a standard normal distribution.

5. Write a function sort_lists to merge sorted integer lists while maintaining order.

Given a list of sorted integer lists, write a function sort_lists to create a combined list while maintaining sorted order without using the ‘sort’ or ‘sorted’ functions in Python.

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

Explain the concept of a p-value in simple terms to a non-technical person. Use analogies or straightforward language to make the explanation clear and understandable.

7. Can you determine if an AB test with unbalanced sample sizes will result in a bias towards the smaller group?

Analyze an AB test with one variant having 50K users and the other having 200K users. Determine if the unbalanced sample sizes will introduce bias towards the smaller group.

8. How would you infer if the results of a landing page redesign AB test are statistically significant?

You want to improve the click-through rate by redesigning a landing page and implementing an AB test. Explain how you would determine if the click-through rate results are statistically significant.

9. Is the difference in average order value between men and women significant?

You have average order value (AOV) data separated by gender: Men (AOV: $46.3, Total purchases: 2500) and Women (AOV: $50.2, Total purchases: 3500). Determine if the difference in AOV is significant.

10. What are the assumptions of linear regression?

List and explain the key assumptions that must be met for linear regression analysis to be valid.

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 Klaviyo interview include:

1. Prepare for Pair Programming: Klaviyo interviews often involve pair programming, so practice working collaboratively on coding problems.

2. Real-World Problem-Solving: Focus on showcasing your ability to solve real-world problems and optimize existing solutions rather than just algorithmic questions.

3. Project-Based Discussions: Be ready to dive deep into past projects you have worked on. Highlight the challenges faced, technical stacks used, and outcomes achieved.

What is the average salary for a Software Engineer at Klaviyo?

What is the culture like at Klaviyo?

Klaviyo’s culture is highly collaborative and supportive. The interviewers aim to create a conversational atmosphere and provide feedback throughout the interview process. It’s important to communicate well and be ready to ask questions and discuss ideas openly.

What should I do if I don’t receive feedback after my interview?

If you don’t receive feedback after your interview, following up with your recruiter is a good idea. While some candidates have reported being “ghosted,” many others have had positive experiences with Klaviyo’s recruitment team. Persistence can sometimes make a difference in getting the feedback you need.

Klaviyo offers software engineers a coveted opportunity to work on customer-facing features and impactful projects. While every interview journey might present unique experiences, Klaviyo’s commitment to a rigorous yet enjoyable interview process signifies its dedication to hiring top-tier talent.

For more insights about the company, check out our main Klaviyo Interview Guide, where we have covered many interview questions that could be asked. We’ve also created interview guides for other roles, such as software engineer and data analyst, where you can learn more about Klaviyo’s interview process for different positions.

For better preparation, you can also check out all our company interview guides, and if you have any questions, don’t hesitate to contact us.

Good luck with your interview!