Snap Software Engineer (SWE) Interview Guide

Technical questions at Snap fall into 2 categories: coding and systems design. As we've mentioned, coding standards at Snap are quite high, so in addition to writing accurate, fast, bug-free code, you should showcase strong problem-solving skills and flexibility.

You'll want to study fundamentals like:

• Data Structures: Arrays, stacks and queues, linked lists, hash tables, etc.
• Algorithms: BFS/DFS, searching and sorting algorithms, etc.

We recommend practicing at a Leetcode medium-hard level in a simulated interview environment to make the most of your prep time. Many interviewees reported being asked infamously difficult dynamic programming questions, so be sure to study up!

Interviewees reported technical questions having to do with:

• Recursive algorithms
• Building a basic calculator
• 2D arrays
• Hash tables

Check out Exponent's SWE interview question bank for more examples.

Systems design questions are more open-ended than coding questions and are designed to test your thought process as well as your knowledge of high-level technical concepts. If you can strike the right balance between structured thinking and creativity, your chances of acing these questions is good.

Some general example questions involve architecting a video distribution system or designing a mobile image search client, but Snap may ask you to work on a Snap product. For example, you may be asked to design a photo sharing service. Alternatively, your interviewers may choose to give you a problem from your domain - for example, if you worked on a payment system, they may ask you to design one.

The best way to prepare for system design interviews is to:

• Review the fundamentals including web protocols, API design, replication strategies, etc.
• Watch a few system design mock interviews such as "Design TikTok."
• Try a few self-guided practice problems, like this one on designing a web crawler.
• When you're ready, sign up for a peer-to-peer system design mock.

Snap's culture and values are important to the company, so you'll be asked behavioral questions throughout, as well as undergo a lunch "interview" with a cross-functional team member. Behavioral questions vary, but expect to be asked about:

• Your background: Any experience listed on your resume is fair game.
• Your impact: Specific examples and the resulting impact of previous work.
• Your ability to self-reflect and learn: What did you learn from past experiences? Successes? Failures?
• Your motivations: Why engineering? Why Snap?

To prepare, we recommend creating a story bank of stories and experiences that would be relevant to your Snap interview, based on their company values which include:

• We Are Kind: We operate with courage, show empathy, and instill trust through honesty and integrity.
• We Are Smart: We solve problems through action, make high-quality decisions, and think with a strategic mindset.
• We Are Creative: We gracefully manage ambiguity, cultivate innovation, and demonstrate an insatiable desire to learn.

You may also want to review Snap's engineering values here:

• Customer Focus: We do what is right for our customer, Snap, and our team, respectively. Positive and successful teams commit to the mission and to each other. Instead of serving themselves, they serve one another.
• Execution: We focus on the key inputs and deliver them with the right quality and in a timely fashion. We never settle. Ideas are easy, execution is everything.
• Craftsmanship: The care we put into our work is what delights our customers and makes them love Snap. Fast and good are not mutually exclusive. We are curious and always seek to learn and improve our skills.
• Creativity: Software engineering is a creative process. While our key metrics are vital in how we manage our business, sometimes the right solution can't be achieved just by optimizing metrics. We take risks and don't let setbacks derail our pursuit of innovation. We learn from our customers, iterate early and often and learn from our mistakes.
• Accountability: We understand how our work impacts others and we own our mistakes. We write code with the future reader and maintainer in mind and realize a project is not finished when shipped; 80% of execution happens post-launch.
• Empathy: We assume the most favorable interpretation and give the benefit of doubt, listening and seeking to understand why people have the positions they do in order to come to the best conclusions. When we disagree, we are respectful and humble towards each other. We create a safe and inclusive workplace and embrace different thoughts, people and backgrounds which allows each of us to be uniquely ourselves. Diversity makes us better.
• Integrity: We are consistent between our words and actions, regardless of the situation or audience. We are not afraid to speak up or disagree. Once the decision is made, we commit to its success fully even if the decision wasn't what we wanted.
• Audacity: Thinking small is a self-fulfilling prophecy. We create bold objectives that inspire results.

When answering questions, we always recommend using the STAR format to avoid rambling. Of course, the best way to prepare is to practice behavioral interview questions.