Upstart interview notes, page 4 of 10

Mid-sized

Most of these Upstart write-ups come from Software Engineers (51), then Data Scientists (42) and Machine Learning Engineers (2). The most reported rounds are the technical phone screen (73), the behavioral / leadership round (8), the online assessment (4) and the multi-round onsite (4).

97 interview notes · updated Jul 2026

Upstart·Data Scientist·Onsite - Behavioral / Leadership

May 2026

Behavioral rounds at Upstart for a Data Scientist role, meeting with the hiring manager and a few cross-functional partners. Pretty standard loop but the cross-functional piece made it feel a bit more involved than a typical screen.

Tell me about yourself and why this role interests you.
Walk me through a cross-functional project you led and how you got buy-in from stakeholders who weren't directly under you.
Give an example of a time you had to move forward on a project without having all the information you needed.

“I always fumble the opener a little.”

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Upstart·Software Engineer·Technical Phone Screen

May 2026

Probability interview at Upstart for a Research Engineer role. The whole thing was basically a deep dive into conditional probability through the classic boy-girl family puzzle and its variants. Not a bad experience but you really need to have your Bayesian intuition sharp.

A family has two children and you know at least one is a boy. What is the probability both children are boys?
Same two-child family, but now you're told the older child is a boy. What's the probability both are boys?
A family has two children and at least one is a boy born on a Tuesday. What is the probability both children are boys?
Extend the problem to three children. Given that at least one is a boy, what is the probability all three are boys?

“Classic puzzle but I still second-guessed myself mid-answer.”

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Upstart·Software Engineer·Technical Phone Screen

May 2026

Upstart interview that was basically one big question about your current project, but don't let that fool you into thinking it's easy prep.

Walk me through what you're currently working on: the project's purpose, your specific role in it, the technical decisions you made, and the challenges you ran into. Be ready to discuss trade-offs, outcomes, and any metrics.

“This sounds like a softball but it really isn't.”

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Upstart·Software Engineer·Technical Phone Screen

May 2026

Coding round at Upstart for a software engineer role, pretty much one meaty problem around string decryption and cipher logic. Not the hardest thing I've done but the edge cases caught me slipping.

Given an encrypted string and a character-mapping rule, implement a decryption function. Handle edge cases like unmapped characters, case sensitivity, ambiguous decodings, and input validation.

“I went straight to the basic substitution case and got that working fine.”

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Upstart·Software Engineer·Online Assessment (OA)

May 2026

Took an OA for a software engineer role at Upstart. Three algorithm problems, nothing too wild, but the grid removal one tripped me up more than I expected.

Given an m x n grid of 0s and 1s, remove blocks one at a time such that you can only remove a block if no block exists to its right in the same row. Return a valid removal order as a list of coordinates.
Given an integer array and a target value, return any two distinct indices whose elements sum to the target. Aim for linear time.
Given an integer array, return the minimum absolute difference between any two distinct elements.

“This one took me longer than it should have.”

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Upstart·Software Engineer·Technical Phone Screen

May 2026

Upstart software engineer interview with a string manipulation problem. Pretty focused on edge cases and the details really mattered here.

Given a list of keywords and a sentence string, return the sentence with all words matching the keyword list removed. Preserve the order of remaining words and handle case sensitivity, punctuation, and whole-word matching correctly.

“The base logic isn't hard but the edge cases piled up fast.”

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Upstart·Data Scientist·Onsite - Multi Round

May 2026

Statistics-heavy onsite round at Upstart for a data scientist role. Three questions, all technical, all with some real bite to them. Not the kind of round where you can coast on intuition.

A population has one-, two-, and three-child families. Given a sample of 100 children (not families), estimate the proportion of each family type and construct a 95% confidence interval.
Why does regressing Y on X give a different slope coefficient than regressing X on Y, and how does this relate to causal direction?
A regression model has no statistically significant coefficients but still shows strong predictive performance. What's going on statistically, and how would you address it?

“This one tripped me up more than I expected.”

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Upstart·Software Engineer·Technical Phone Screen

May 2026

Interviewed for a Research Scientist role at Upstart and got hit with a stats theory question that looked straightforward on the surface but required you to actually know the math cold.

In simple linear regression, regressing Y on X gives one slope and regressing X on Y gives another. Why aren't those two slopes simply reciprocals of each other? Walk through the math and explain the geometric intuition.

“I knew the formulas going in but the geometric part tripped me up more than I expected.”

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Upstart·Software Engineer·Technical Phone Screen

May 2026

Coding round at Upstart for a software engineer role. The problem was a cipher-based decryption puzzle where you had to reconstruct substitution keys from known plaintext pairs and use them to peel back a double-encrypted message. Niche setup but the core logic wasn't too bad once I mapped it out.

Given known plaintext and ciphertext pairs for two substitution ciphers, reconstruct the decryption mappings and use them to decrypt a message that was encrypted sequentially by both ciphers (in reverse order).

“The setup took me a minute to parse.”

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Upstart·Software Engineer·Technical Phone Screen

May 2026

Coding round at Upstart for a software engineer role. One problem, fairly focused, centered on string decoding with chained hash map lookups. Not a brutal interview but the constraint framing kept me second-guessing myself.

Given a ciphertext string and two HashMaps, decode the string by mapping each character through the first map and then mapping that result through the second map. Implement this in O(n) time.

“Two lookups per character, so I kept overthinking whether chaining them violated the O(n) requirement.”

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