Robinhood Coding Interview Questions
25 Robinhood coding interview problems with full optimal solutions — 5 easy, 16 medium, 4 hard. Every problem ships with multiple approaches (brute-force first, then the optimal), complexity tables for each, company-specific tips on what an Robinhood interviewer values, and a FAQ section.
Showing 5 problems of 25
- #1easyfoundational
1. Two Sum
Two Sum is Robinhood's most reliable phone-screen warm-up: given an integer array and a target, return the indices of the two numbers that sum to the target. The interviewer is watching whether you narrate the brute-force-to-hash-map tradeoff before coding the optimal.
3 free resourcesSolve → - #20easyfoundational
20. Valid Parentheses
Given a string of brackets, determine whether the string is valid. At Robinhood this is a classic 15-minute warm-up that tests whether you reach for a stack instantly and handle empty-stack edge cases without prompting.
3 free resourcesSolve → - #121easycompany favorite
121. Best Time to Buy and Sell Stock
Given an array of daily stock prices, return the maximum profit from a single buy and sell. This is the most thematically on-brand question Robinhood asks — and they ask it specifically to test whether you reach for the one-pass min-tracking trick versus a brute-force pair search.
3 free resourcesSolve → - #206easyfoundational
206. Reverse Linked List
Given the head of a singly linked list, reverse the list and return the new head. Robinhood asks this as a 10-minute warm-up on phone screens — they're checking pointer fluency and whether you can do it iteratively without leaking nodes.
3 free resourcesSolve → - #359easyfrequently asked
359. Logger Rate Limiter
Design a logger system that returns whether a unique message should be printed in a given timestamp; the same message cannot reprint within 10 seconds. Robinhood asks rate-limit design because production trading services need request throttles that can't break under load.
3 free resourcesSolve →
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