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 →
Related interview-prep guides
CodeSignal GCA for Tech Interviews in 2026: The Complete Guide
The CodeSignal General Coding Assessment is a 70-minute, four-task timed test scored on a 600 to 850 scale, used as a filter by Goldman Sachs, Capital One, Robinhood, Brex, and a growing list of tech and finance employers. This guide breaks down what it tests, how it scores, what it records during your session, and how to practice for it.
Karat Technical Interview Guide 2026: How the Third-Party Loop Actually Works
Karat is technical-interview-as-a-service. Karat-employed engineers run the technical loop for the hiring company in Karat's own recorded video and coding environment. The dynamic is different from an in-house interview: the interviewer is a contractor, not a future teammate, the rubric is fixed, the session is recorded for asynchronous review, and the hiring team's engineers watch the playback a day later. This guide is the practical map of how that loop works in 2026 and how to prepare for it.
CodeInterview.io Live Coding Interview Guide (2026): What the Platform Tracks and How to Walk Through It Cleanly
CodeInterview.io is a browser-based collaborative live-coding platform. Think of it as a lighter-footprint alternative to CoderPad with an integrated video call, per-keystroke replay, and a drawing whiteboard. Smaller market share than CoderPad but shows up at a meaningful slice of YC startups and mid-market tech teams in 2026. This is what CodeInterview.io tracks, how its all-in-one workflow compares to CoderPad, and how to walk through a live round cleanly.