vercel

Mid-sized

Vercel is a cloud platform for frontend developers that enables building, deploying, and scaling web applications. It is the creator of the popular Next.js React framework and is known for its focus on developer experience and edge-optimized hosting.

3 interview notes · updated Jul 2026

vercel·Software Engineer·Onsite - System Design / Architecture

Jun 2026

System design round at Vercel for a software engineer role. Just one question but it took up the whole session, which I wasn't fully expecting.

How would you design a collaborative document editing system similar to Google Docs?

“This is one of those questions where you think you know it until you're actually drawing it out.”

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vercel·Software Engineer·Technical Phone Screen

May 2026

Vercel software engineer interview with a real-time systems coding problem. Pretty practical setup, no LeetCode nonsense, just a scenario ripped from actual product work.

A product team forgot to add analytics before a webpage launch. Implement two functions: one to record a hit with a timestamp, and another to return the count of hits in the last 5 minutes. Then optimize for very high traffic volumes.

“Started with a deque and just popped off anything older than 5 minutes on each call.”

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vercel·Software Engineer·Technical Phone Screen

May 2026

Vercel software engineer interview with a backend coding problem focused on real-time metrics. Pretty standard stuff but the follow-up pushed into system design territory which I wasn't fully ready for.

Build a hit counter with two operations: one to record a hit at a given timestamp, and another to return the total hits in the last 300 seconds up to a given timestamp. How would you implement this efficiently in both time and memory?
If hits per second can be extremely high, how would you redesign the counter to avoid storing one entry per individual hit?

“My first instinct was just a list and filter everything older than 300 seconds on each query call.”

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