Vercel Coding Interview Questions
100 Vercel coding interview problems with full optimal solutions — 30 easy, 64 medium, 6 hard. Every problem ships with multiple approaches (brute-force first, then the optimal), complexity tables for each, company-specific tips on what an Vercel interviewer values, and a FAQ section.
Showing 8 problems of 100
- #1easyfrequently asked
1. Two Sum
Given an array of integers and a target, return the indices of two numbers that add up to the target. Vercel asks this as a warm-up to test whether you reach for a hash map instinctively when you see a 'find a pair' problem in their edge-routing or cache-key dedup contexts.
- #2easyfrequently asked
2. Valid Parentheses
Given a string of brackets, decide if it's balanced. Vercel uses this to test whether you recognize the stack pattern instantly — it's the same shape as their route-segment matching in nested layout trees.
- #3easyfrequently asked
3. Merge Two Sorted Lists
Merge two sorted linked lists into one sorted list by splicing nodes together. Vercel asks this as the building block of their log-merge sub-question for edge-function telemetry — same pattern as merging sorted per-region access logs.
- #12easyfrequently asked
12. Maximum Depth of Binary Tree
Given a binary tree, return its maximum depth. Vercel asks this to confirm you can do the 'max + 1' recursive pattern — the same trick they use to compute the longest deployment dependency chain.
- #16easyfrequently asked
16. Best Time to Buy and Sell Stock
Given an array of stock prices, find the max profit from a single buy-then-sell. Vercel asks this because the 'track min so far' pattern is identical to how their edge analytics finds the cheapest-cost path over a time-series of latencies.
- #19easyfrequently asked
19. Linked List Cycle
Given a linked list, determine whether it has a cycle. Vercel asks this because Floyd's tortoise-and-hare is the gateway to a class of pointer-pacing tricks they use in their request-pipeline scheduler.
- #29easyfrequently asked
29. Reverse Linked List
Reverse a singly linked list in-place. Vercel asks this constantly because it's the building block of every list-manipulation problem they care about — and because they want to see if you can do both iterative and recursive cleanly.
- #30easyfrequently asked
30. Contains Duplicate
Given an array, return true if any element appears more than once. Vercel asks this as the simplest set-based question; it's the warm-up before they pivot to streaming dedup or cache-key collisions.