Upstart Fulltime Machine Learning Engineer Onsite Interview Experience
Question Details
Screening 1 - stats, probability,
coding An atom has a half-life of 1 day. What is the probability that 100 atoms will survive for 10 days? Code for simulation
Follow-up How to improve Total Quality
Full Details
Screening 1 - stats, probability,
coding An atom has a half-life of 1 day. What is the probability that 100 atoms will survive for 10 days? Code for simulation
Follow-up How to improve Total Quality (TC) and why it works? Leverage the NumPy size argument; vectors are stored in memory closely, therefore faster to fetch. The following content requires a score higher than 160. You can already view it. Screening 2 - ML
coding Implement decision tree
Onsite ML
coding - Standard ML questions - LeetCode (likely 3sum) - The Nth prime number BE: Deadline and conflicts related Thoughts: The probability and statistics questions were largely similar to those in previous interviews, but they might have evolved into coding or simulation questions. Without prior interview experience, I personally found the coding questions more difficult. After being notified of the interview, I had separate interviews with the hiring manager and virtual manager, only to find out that they had stopped hiring for the MLE program... This company is really a trap.
About This Question
This is a reported interview question from a upstart interview for a mle role during the onsite round reported in 2025.
It covers the following topics: Tree .
Difficulty rating: Hard
Topics
About Upstart Interview Reports
This question was reported by a candidate who interviewed at Upstart. 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 Upstart are the higher-signal extractions to take from this report.
For broader preparation context, the Upstart 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 Upstart reports consistently are the ones worth investing in; one-off niche problems are not.
During Your Upstart 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 Upstart 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.