Data Scientist Coding & Algorithms Interview Questions
Practice 335 real Coding & Algorithms interview questions for Data Scientist roles. From companies including Amazon, Google, Two Sigma, Pinterest, Uber.
"I got asked a hardcore MCM DP question and I saw it on PracHub as well. Solved that question in 5 minutes. Without PracHub I doubt I could solve it in 5 hours. Though somehow didn't get hired, perhaps I guess I solved it too fast? /s"
"Believe me i'm a student here jn US. Recently interviewed for MSFT. They asked me exact question from PracHub. I saw it the night before and ignored it cause why waste time on random sites. I legit wanna go back and redo this whole thing if I had chance. Not saying will work for everyone but there is certainly some merit to that website. And i'm gonna use it in future prep from now on like lc tagged"
"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."
Maximum-Product Simple Path in a Complete Directed Graph
You are given a complete directed graph with n nodes labeled 0 through n - 1. For every ordered pair of distinct nodes (i, j), there is a directed edg...
Count Distinct Island Shapes in a Binary Grid
You are given an m x n binary grid grid, where grid[i][j] is either 0 (water) or 1 (land). An island is a maximal group of 1-cells connected 4-directi...
Maximize profit from one or many stock trades
You are given an integer array prices where prices[i] is the price of a stock on day i (0-indexed). Answer the following two subproblems: 1. Single tr...
Find smallest N for 5-and-21 sums
You are given two positive integers: 5 and 21. We say a positive integer x is representable if it can be written in the form \[ x = 5a + 21b \] for so...
Match payments to invoices by memo or amount
Scenario You are building a small reconciliation tool that matches payments to invoices. Data structures Assume you are given: - invoices: a list of i...
Compute win probability in coin-toss game
Two players, A and B, play the following game with a fair coin: - They toss the coin alternately: A tosses first, then B, then A, then B, and so on. -...
Match payments to invoices by memo or amount
You are building a small payment-to-invoice matching utility. Data You are given: - invoices: a list of invoice records with: - invoice_id (string) ...
Find top-5 most similar rows across datasets
You are given two datasets with the same feature columns: - source (rows you want to match): - source_id (STRING/INT) - f1...fk (NUMERIC; may cont...
Implement minimal-cost overtime/contractor allocation
You must cover H extra engineering hours this week at minimum cost using employee overtime and optional contractors. Each employee i has a maximum ove...
Implement percentage RMSE and bootstrap its CI
Given a CSV with columns [country, actual_revenue, predicted_revenue], define percentage RMSE as pRMSE = sqrt(mean_i((pred_i/actual_i − 1)^2)). a) Imp...
Solve two-sum variants at scale
Base task: Given nums = [3, 1, 2, 2, 4] and target = 4, return the 0-based index pair (i, j) with i < j such that nums[i] + nums[j] = target. If multi...
Implement an LRU cache with O(1) ops
Design and code an LRU cache supporting get(key) and put(key, value) in O(1) average time with capacity N. Specify your data structures, handle update...
Classify relationships for multiple circle pairs
Given an array pairs of N circle pairs, where each circle is (x, y, r) with integer coordinates and r ≥ 0, classify each pair into one of: IDENTICAL (...
Maximize outfits with distinct colors
You're given counts of items by color; each outfit must contain exactly 3 items, all of distinct colors. You cannot reuse items. Input formats: either...
Implement longest increasing subarray with one deletion
Given an array of integers nums, return the length of the longest strictly increasing contiguous subarray you can obtain by deleting at most one eleme...
Implement max profit with K transactions (DP)
Given an array prices[0..n-1] of daily stock prices and an integer k, implement a bottom-up dynamic program to compute the maximum achievable profit w...
Implement streaming autocomplete under tight memory
Build an autocomplete service: Input: a list of up to 5,000,000 UTF-8 words (may include accents and hyphens), each with an integer popularity score t...
Generate primes up to n efficiently
Implement a function that returns all prime numbers in the inclusive range 1..n. Requirements: handle n up to 10^7 efficiently (time and memory); retu...
Implement multiplication without using the multiplication operator
Implement int multiply(int a, int b) without using * or /. You may use +, −, bitwise operators, and shifts. Requirements: - Handle negatives, zero, an...
Implement longest subarray summing to k
Given an integer array nums (length ≤ 200,000; values may be negative) and integer k, return the maximum length and the [l, r] indices of a contiguous...