Robinhood Onsite Fulltime SDE Interview: Load Factor and API Design Challenges
Question Details
Yunnan-Burma: Classic load factor (https://www.hack2hire.com/companies/robinhood/coding-questions/67cf7c4eaca6a2fa74a72d1c/practice?questionId=67cf7ef7aca6a2fa74a72d1f) VO: PDD: Normal behavioral ques
Full Details
Yunnan-Burma: Classic load factor (https://www.hack2hire.com/companies/robinhood/coding-questions/67cf7c4eaca6a2fa74a72d1c/practice?questionId=67cf7ef7aca6a2fa74a72d1f) VO: PDD: Normal behavioral questions. Presenting a project requires a PPT; the recruiter told me a maximum of two pages. SD: Classic job scheduler, but unique in that job run failures do not require retrying.
Coding Seems to be a new question (at least I haven't seen it on Geography). Given a list of APIs ["1/REGISTER/user1/100", "2/REGISTER/user2/200"", "3/FRIEND_REQUEST/user1/user2", "4/ACCEPT_FRIEND/3", "5/SEND_MONEY/user1/user2/50"], write a function to return the final balance of all registered accounts. This example returns "1:50, 2:250". This mainly tests extensibility and design patterns. The first number for each API is the request_id. The parameters for the register API are user_id and the initial balance. friend_request is user1 and user2, and accept_friend is the request_id. Money cannot be sent between two users who are not friends.
About This Question
This is a reported interview question from a robinhood interview for a swe role during the system design round reported in 2025.
It covers the following topics: Api Design .
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About Robinhood Interview Reports
This question was reported by a candidate who interviewed at Robinhood. LeakCode aggregates interview reports from 10+ sources, including 1Point3Acres, Glassdoor, LeetCode Discuss, Blind, Reddit, Indeed, and Nowcoder. Each report is translated where necessary, deduplicated against existing entries, and tagged by company, role, round type, and reporting date.
Use this question as one calibration data point, not a memorization target. Companies typically rotate their question pools every 2-4 months; the exact wording of a 2024 question may differ from what you encounter today. The underlying pattern, difficulty level, and follow-up depth at Robinhood are the higher-signal extractions to take from this report.
For broader preparation context, the Robinhood interview process typically includes a recruiter screen, one or two technical phone screens, and a 4-5 round on-site loop covering coding, system design (at L4+ levels), and behavioral. Reports tagged on LeakCode show the round-by-round distribution and typical difficulty calibration. To browse questions filtered by round type and seniority, use the company hub linked above.
How To Practice This Type of Question
Solve similar problems on LeetCode under timed conditions (25-35 minutes per medium difficulty). The goal is pattern recognition: recognize the underlying technique (sliding window, two-pointer, BFS, memoized recursion, etc.) within 60-90 seconds of reading. Strong candidates verbalize their hypothesis out loud before coding, then iterate based on feedback. Weak candidates dive into implementation immediately, lose time on the wrong approach, and run out of time for follow-ups.
Companies update their question pools every 2-4 months. The exact wording of any given question may have been retired by the time you interview. Focus your prep on the pattern, not the specific problem. The patterns that appear in Robinhood reports consistently are the ones worth investing in; one-off niche problems are not.
During Your Robinhood Round
Apply the standard interview round template: clarify requirements (2-3 minutes), state your approach out loud and confirm direction with the interviewer (3-5 minutes), code with narration (15-25 minutes), test with concrete examples including edge cases (5 minutes), discuss optimization or trade-offs if time permits (5 minutes). This template is universally accepted across FAANG and adjacent companies; deviating from it produces weaker interviewer feedback signal.
The single most predictive failure mode in Robinhood reports tagged "no hire": not asking clarifying questions. Interviewers are explicitly trained to weight this. Strong candidates ask 3-5 clarifying questions even on problems that look obvious; weak candidates dive into code immediately. The clarifying-question check is often the first signal recorded in the interviewer's written notes.