Upstart Interview Questions
Practice the exact questions companies are asking right now.
"10 years of experience but never worked at a top company. PracHub's senior-level questions helped me break into FAANG at 35. Age is just a number."
"I was skeptical about the 'real questions' claim, so I put it to the test. I searched for the exact question I got grilled on at my last Meta onsite... and it was right there. Word for word."
"Got a Google recruiter call on Monday, interview on Friday. Crammed PracHub for 4 days. Passed every round. This platform is a miracle worker."
"I've used LC, Glassdoor, and random Discords. Nothing comes close to the accuracy here. The questions are actually current — that's what got me. Felt like I had a cheat sheet during the interview."
"The solution quality is insane. It covers approach, edge cases, time complexity, follow-ups. Nothing else comes close."
"Legit the only resource you need. TC went from 180k -> 350k. Just memorize the top 50 for your target company and you're golden."
"PracHub Premium for one month cost me the price of two coffees a week. It landed me a $280K+ starting offer."
"Literally just signed a $600k offer. I only had 2 weeks to prep, so I focused entirely on the company-tagged lists here. If you're targeting L5+, don't overthink it."
"Coaches and bootcamp prep courses cost around $200-300 but PracHub Premium is actually less than a Netflix subscription. And it landed me a $178K offer."
"I honestly don't know how you guys gather so many real interview questions. It's almost scary. I walked into my Amazon loop and recognized 3 out of 4 problems from your database."
"Discovered PracHub 10 days before my interview. By day 5, I stopped being nervous. By interview day, I was actually excited to show what I knew."
"I recently cleared Uber interviews (strong hire in the design round) and all the questions were present in prachub."
"The search is what sold me. I typed in a really niche DP problem I got asked last year and it actually came up, full breakdown and everything. These guys are clearly updating it constantly."
Decrypt a twice-encrypted message using known pairs
Three people pass notes A → B → C → A. Notes are encrypted using a character-substitution cipher (a one-to-one mapping per character). You are given t...
Reverse even numbers in a list
Given an integer array nums, remove all odd numbers and return the remaining even numbers in reverse order (preserving no other ordering constraints)....
Decode an anagram sentence using vocabulary constraints
You are given: - vocab: a list of lowercase words (the "dictionary") - s: a string containing space-separated scrambled words Each scrambled word in s...
Compute buffet revenue with capacity and waiting
A casino buffet has a maximum capacity capacity (number of customers that can be seated at once). You are given: 1) prices: an array where prices[i] i...
Estimate impact without experiments and pick variant
Part A — Measuring impact when you cannot run an experiment You are a Staff Data Scientist working on a product change (feature/policy/model update). ...
Correct length-biased sampling from family-size survey
In a town, you visit a school and ask 100 kids: “How many children are in your family?” You observe: - 50 kids say their family has 1 child - 20 kids ...
Implement factorial and count trailing zeros
Answer the following coding questions in Python. 1) Implement factorial Implement a function factorial(n) that returns \(n!\) for a non-negative integ...
Compute decay, OLS, and classic probability results
You are asked several probability/statistics questions. 1) Radioactive decay (half-life) A radioactive atom has a half-life of 1 day. Assume each atom...
Solve drunk-passenger probability and simulate outcome
Lost Boarding Pass Puzzle: Last Passenger's Seat Context: Technical screen for a Data Scientist (Statistics & Math). Setup - There are n passengers la...
Implement four string-processing functions
You are given four independent string/list problems. Implement each as a separate function. 1) Filter strings by shared characters Input: - words: a l...
Find max word letter span
Implement a function that, given an input text string, computes the maximum word letter span and returns both (a) the maximum span and (b) the list of...
Analyze HT vs HH stopping-time probabilities
Coin-Flip Stopping Game: HT vs HH You repeatedly flip a coin until either the pattern HT appears (Player A wins) or the pattern HH appears (Player B w...
Explain L1 vs L2 and ridge vs lasso
Explain the differences between: 1. L1 vs L2 regularization (how they change the objective, geometry/intuitions, and typical effects on learned parame...
Solve remembered OA coding tasks
The online assessment reportedly had five coding questions, but only the following three were described clearly enough to reconstruct: 1. Find the top...
Combine noisy thermometers; compute random-walk correlations
Problem 1: Estimating a true temperature from noisy thermometers Assume the true (fixed) temperature is an unknown constant \(\theta\). 1a) One thermo...
Interpret A/B results with p-values and uncertainty
A/B Test: Effect Sizes, CIs, Multiple Testing, Power, and Decision Context: You ran a 14‑day experiment (2025‑08‑15 → 2025‑08‑28) with 1:1 allocation ...
Implement PAVA spend-smoothing under no-borrowing constraint
Monotone Spending Plan via Isotonic L2 Regression (No-Borrowing) Context: You observe yearly discretionary income profit[1..65] (nonnegative reals) an...
Identify binomial model and compute moments
Tossing N Balls Into a Cup (Independent Hits with Probability p) You toss N independent balls toward a cup. Each ball lands in the cup with probabilit...
Decide to ship a signup experiment
A/B Test Plan: Redesigned User Signup Flow Context and Data You are analyzing an A/B experiment for a redesigned user signup flow. The dataset include...
Calculate Expected Streaks in Coin Toss Sequence
Expected Number of Streaks in Coin Tosses Scenario You toss a coin repeatedly. A "streak" (a run) begins on the first toss and whenever the current to...