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Cloudflare

Large Enterprises

Screna has 17 Cloudflare interview write-ups. The most reported round is the technical phone screen (8).

17 interview notes · updated Jul 2026

Cloudflare·Software Engineer·Onsite - Behavioral / Leadership

Jul 2026
Behavioral round at Cloudflare for a software engineer role. Just the one question about a recent project, which sounds easy until you're actually in it trying to figure out how much context to give versus how much to just skip to the good stuff.
  • Walk me through a recent project you worked on and explain your specific contributions to it.

“The tricky part isn't describing the project, it's resisting the urge to just narrate the team's work and forgetting to say what you actually did.”

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Cloudflare·Software Engineer·Technical Phone Screen

Jul 2026
Interviewed for a software engineering role at Cloudflare. The conversation included a question about product familiarity that I wasn't totally sure how to handle, especially since it can go a few different ways depending on your actual usage history.
  • Have you used any of our products before? What was your experience with them?

“This one tripped me up a bit because I wasn't sure how deep to go.”

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Cloudflare·Software Engineer·Technical Phone Screen

Jul 2026
Interviewed for a software engineer role at Cloudflare. The technical portion involved walking through a recent project and then getting pushed to go deeper on the implementation details, which is where things got a little uncomfortable.
  • After giving a high-level overview of a recent project, the interviewer asked you to walk through the technical details more specifically. How did you break it down?

“I rambled a bit at first.”

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Cloudflare·Software Engineer·Technical Phone Screen

Jul 2026
Interviewed for a software engineer role at Cloudflare. The technical screen touched on engineering practices, specifically around code review, which sounds routine until you realize they want to know if you actually think about it or just rubber-stamp PRs.
  • Have you done code reviews before, and if so, how do you approach them?

“Seemed like a warmup question but the follow-up is where it gets real.”

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Cloudflare·Software Engineer·Onsite - System Design / Architecture

Jun 2026
Cloudflare systems design round focused entirely on building an encrypted key-value store from scratch. Pretty deep dive, more implementation-heavy than I expected for a design interview.
  • Design and implement an encrypted key-value store where values are encrypted at rest using a user-supplied password. Include put, get, delete, and list operations, plus user registration and login.
  • How would you handle key derivation from a user password? Walk through your choice of algorithm, the role of salt, and how you'd store what's needed to re-derive the key on login.
  • For each write operation, how do you handle the IV or nonce, and why does it need to be unique per write rather than per user?
  • What happens when a user provides the wrong password during a get operation? How does your system detect and surface that error?

“This is where I spent most of the session.”

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Cloudflare·Software Engineer·Onsite - System Design / Architecture

Jun 2026
System design round at Cloudflare for a software engineer role, focused entirely on building an encrypted key-value store with user auth. Pretty deep on crypto primitives and threat modeling, which I wasn't fully expecting.
  • Design a key-value store that supports user login and stores values encrypted at rest using the user's own password.
  • How would you handle a password change without losing access to existing encrypted values?
  • What does your threat model look like, and what attacks does your design protect against versus not protect against?

“This question sprawled way more than I expected.”

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Cloudflare·Software Engineer·Onsite - Behavioral / Leadership

Jun 2026
Behavioral round at Cloudflare for a software engineer role. Just the one question about code review conflicts, which sounds easy until you're actually in the seat trying not to sound like you've never disagreed with a coworker in your life.
  • How do you handle disagreements with teammates during code reviews, whether about implementation choices or broader design decisions?

“I went with a real example where I pushed back on a colleague's approach and we ended up splitting the difference.”

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Cloudflare·Product Manager·Onsite - Behavioral / Leadership

May 2026
Cloudflare PM behavioral round, pretty focused on product ownership and how you think about metrics. Nothing wildly unexpected but the depth they wanted on trade-offs was real.
  • Walk me through a product decision you owned or heavily influenced. What was the problem, what trade-offs did you weigh across users, business, and engineering, and what did you decide?
  • How do you define and measure product success, and what do you do when your metrics are pointing in different directions?
  • How do you take user feedback and actually turn it into roadmap decisions?

“This is the one I spent the most time on and still felt like I rushed the trade-offs section.”

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Cloudflare·Software Engineer·Technical Phone Screen

May 2026
Interviewed for a software engineering role at Cloudflare and got asked about production contributions pretty early on. Felt like a straightforward question but there's actually a lot of ways to fumble it if you're earlier in your career.
  • Have you ever contributed to production code, and what was the impact of your work?

“Sounds easy until you're sitting there trying to figure out how much to say.”

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Cloudflare·Software Engineer·Technical Phone Screen

May 2026
Cloudflare coding round, one question, pretty standard merge k sorted lists problem. Nothing fancy but they clearly wanted you to know your heap basics.
  • Given an array of k sorted linked lists, merge them all into a single sorted linked list.

“I knew this one but still fumbled the heap setup a bit.”

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