How to Prepare for a Security Engineer Interview

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Hey there! This article is part of our series on Security Engineering. If you're interviewing for engineering roles, don't miss our Complete Software Engineering Interview Course.

Security engineering interviews are some of the toughest in the tech industry. As a security engineer, your job is all about reducing risk for technical products by thwarting malicious behavior.

Due to the essential nature of security engineering, the interviews for security engineers can be some of the most challenging in technical interviews.

We sat down with security and cybersecurity engineers from some of the top tech companies including Google, Meta, Amazon, and more to clarify what's actually asked in the security engineer interview and how to prepare.

Security Engineer Interview Stages

In general, the security engineer interview has the following interview stages at most companies:

1. Recruiter screen

In this 30-45min interview, your recruiter will ask questions about your resume, light technical questions to gauge your domain knowledge of security engineering, and behavioral questions to assess your culture fit at the company. In general, try to be authentic and genuine, while also showing that you've done research on the company and are genuinely excited to work there. We often recommend looking up your interviewer on LinkedIn to understand them a bit better, and reviewing public vision documents produced by the company.

2. Manager screen

In this interview, you'll speak with the hiring manager about your technical skills and domain knowledge (this is sometimes referred to as the technical screen). Expect to talk through why you're the best candidate for the job and how you'd add value to the company.

3. On-site

On-site interviews also vary, but they follow a predictable structure. Typically you’ll interview for 3-5 hours total with a lunch break midway through. You’ll go through many rounds, each 30 - 60 minutes long. One of the interviews will be a coding focused interview, where you'll be asked standard algorithms and data structures interview questions. The rest of the interviews will focus more on the methodology of how you'd go about solving some security issues, and is more in a discussion format. We encourage you to gather as much information as possible about the exact structure from your recruiter, as well as reviewing our list of Security Engineer interview questions below.

While this is a generally universal structure of the interview process, the interview stages can vary across different companies. Keep in mind your recruiter is on your side–they can answer questions you have about the interview loop before you go to your on-site.

Security Engineer Interview Questions

As mentioned, security engineer interview questions can vary widely from company to company. Here's a list of questions we've seen most frequently asked at tech companies.

  • How would you approach reducing security vulnerability resolution times across software products? Watch our answer here.
  • When would you use symmetric vs. asymmetric encryption? Read our guide to encryption here.
  • What's the difference between hashing, encryption, and encoding?
  • How would you implement Server Hardening?
  • Implement a cypher to perform basic encoding.
  • How would you protect against a specific type of security attack (e.g. man-in-the-middle)?
  • Tell me about a time you solved a challenging security problem and how you resolved it.
  • What sort of anomalies would you look for to identify a compromised system?
  • What tools and approaches would you use for penetration testing?
  • Given a specific scenario, how would you consider threat modeling?
  • Describe what happens when you type www.google.com into your browser.
  • How would you detect a DDOS attack?
  • How would you prevent buffer overflows and memory leaks?
  • How do you think about the different types of firewalls and when you would implement each one?
  • General conceptual questions (e.g. why is IAM important?)

Preparing for the Interview

1. Review the Fundamentals

To be successful in the security engineer interview, we strongly recommend reviewing security engineering fundamentals. Some of the fundamental pieces of knowledge you'll want to review includes this glossary below:

  • IAM (Identity and Access Management): the process by which the correct people access the correct resources to perform their job. Goals of IAM include employee performance and security.
  • ABAC (Attribute based access control): also known as policy-based access control for IAM, and is an authorization model that leverages characteristics (aka attributes) to assign access controls.
  • TCP Handshake: a three-way communication protocol to ensure connectivity between devices.
  • IoC (Indicators of Compromise): refers to the set of evidence that implies a security breach may have occurred.
  • Server Hardening: a process to secure components and functions of a server in service of reducing the vulnerability of the server from attacks.
  • Hashing: the process to change a given piece of information into another value, in security usually used for the purpose of encryption.
  • Encryption: the method to change information into a code such that only authorized individuals can decipher the code back into the original information.
  • Encoding: the method to transform data in a way that is publicly accessible (e.g. converting from decimal to binary)
  • Symmetric and Asymmetric Encryption: Symmetric encryption uses a single key; asymmetric uses a public/private key pair.
  • Least Privilege Access: the principle that users should have the least-needed set of access privileges to perform their job function.
  • OAuth (Open Authorization): open standard that's used to grant access to websites/apps without a password. One common form of SSO (Single sign-on).
  • SAML (Security Assertion Markup Language): protocol that allows users to access multiple web applications using the same login information. One common form of SSO (Single sign-on).
  • STRIDE: the set of threats to consider–Tampering, Repudiation, Information Disclosure, Denial of Service (DoS), and Elevation of Privilege.
  • MFA (Multi-factor Authentication): users must authenticate with two or more pieces of evidence to gain access to a website/app.
  • WAF (Web Application Firewall): protection for web applications against malicious behavior by monitoring HTTP traffic.

While covering all of these concepts may not be in your initial answer, your interviewer will likely push on your initial answer with follow-up questions related to these concepts. For instance, if you're answering a question on implementing authorization and authentication systems, your interviewer may ask you follow-up questions on how you think about the different solutions including SAML, OpenID Connect, and OAuth.

Looking for more resources? Review this study guide to security engineering interviews at Google.

2. Research the Interview Process for Companies

Each company has its own process for interviewing candidates and evaluates candidates along different core values, so do your homework! If you understand the mission and core values of the companies you're applying to, you'll not only understand more about the company's culture and goals, you'll also be better prepared to demonstrate those values and principles during the interview. We've put together an extensive catalog of interview guides that give you an inside look at the interview process and criteria for most tech companies. Here are a few examples:

Check out our full list of company interview guides here:

Be sure to focus your preparation on the role you're applying for as well. One important tip: always review in detail the job description of the role you're applying for. Often, the job description can indicate what types of questions will come up and what skills the hiring manager is looking for. Tailor your study plan to map to the set of skills and responsibilities listed there.

3. Prepare for Coding Interviews

Security engineer interviews are often asked coding interviews related to security standards. These tend to follow the more common algorithm and data structures interview questions asked in software engineering interviews.

To answer these questions, review the basics of software engineering, including but not limited to sorting algorithms, binary search, graphs and trees, dynamic programming, recursion, arrays, linked lists, stacks, queues, hash tables, heaps, graph search, and more.

Some common or recently asked software engineering interview questions to review and practice:

  • Given an array of intervals, merge the overlapping intervals and return an array of the non-overlapping intervals that cover all intervals in the input. Watch answer.
  • Design an algorithm to merge k sorted linked lists. Watch answer.
  • Given an nxn grid of 1 and 0s, return the number of islands in the input. Watch answer.
  • Write an LRU Cache. View answer.
  • Write a function fib(n) that returns the nth Fibonacci number. Practice answer.
  • You have the value of a stock for the next n days. Given that you can only buy or sell at most 1 share each day, maximize your profit after n days.
  • If there are two strings, which both contain a number larger than 32bit, how do you add them and return the result as a string?
  • Given a list of integers, return a 1 if the number is a power of 2 and a 0 if the number isn't a power of 2.

Coding interviews won't make up the entirety of your interview, but companies like Google are known to spend two to three interviews focused on coding interviews in addition to the conversational security engineer interview questions as well.

4. Practice

Lastly, be sure to get in some practice to get comfortable answering questions and smooth out your responses.

As you practice, remember to actively listen. Effective security engineers know how to actively listen to their team — it's no different in the interview process. After you hear an interview question, take the time to really truly listen to what the interviewer is asking. This means asking follow-up questions and repeating what you hear back to ensure you and your interviewer are on the same page.

After each practice session, reflect on what you think you did well and where you could improve. As you practice, list out common weaknesses so you can notice patterns and improve your performance.

If you're looking to get feedback on your practice, practice on a peer-to-peer mock interview website like Pramp, where you can conduct mock interviews and get detailed feedback on your answers, along with sample questions that you can be asked by your peers.

More Resources

Ultimately, the best way to prepare for the security engineer interview is to get out there and practice. Here are some resources that could be helpful in your preparation:

👯‍♂️ Practice your behavioral and system design skills with our interview practice tool.

👨‍🎓 Take our complete System Design interview course.

🖊️ Software engineering interview cheat sheet

Good luck with your interview preparation journey!

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