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Search in Rotated Sorted Array at Stripe — Interview Guide

How to approach Search in Rotated Sorted Array in a Stripe interview: the optimal approach, what Stripe interviewers look for, and company-specific tips.

Updated 2026-09MediumBinary Search

The problem at Stripe

Search for a target value in an array that was sorted then rotated at an unknown pivot, in O(log n) time.

Stripe uses this problem to assess apis, money, and pragmatic engineering. Expect Stripe-specific follow-ups that tie the solution back to production reasoning and the company's engineering bar.

Key concepts

At each mid, one half is always sorted; identify it by comparing nums[mid] with nums[left].
If the target lies in the sorted half, search there; otherwise search the other half.
Handle duplicates carefully — when nums[left] == nums[mid] you cannot tell which side is sorted.

Approach

def search(nums, target):
    l, r = 0, len(nums) - 1
    while l <= r:
        m = (l + r) // 2
        if nums[m] == target: return m
        if nums[l] <= nums[m]:
            if nums[l] <= target < nums[m]: r = m - 1
            else: l = m + 1
        else:
            if nums[m] < target <= nums[r]: l = m + 1
            else: r = m - 1
    return -1

What Stripe looks for

Pragmatic engineering — code that works and is maintainable.
API and product thinking — design interfaces developers love.
User empathy — Stripe cares deeply about developer experience.
Clarity in writing and communication.

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