Data Scientist Coding & Algorithms Interview Questions
Practice 313 real Coding & Algorithms interview questions for Data Scientist roles. From companies including Amazon, Google, Pinterest, Uber, Capital One.
"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."
Detect k events in a sliding window
Implement an algorithm that, for each user, determines whether there exists a set of at least k ACH credit events from distinct device_ids within any ...
Implement lower_bound on unknown-size sorted array
Lower Bound in Unknown-Length Nondecreasing Array via API Setup You are given a non-decreasing integer array A of unknown length n. You cannot access ...
Design a Scalable, Fault-Tolerant Distributed Order System
Scenario Round covering distributed-system design and algorithm implementation. Question Design a highly available, low-latency distributed order-proc...
Calculate 95% Bootstrap Confidence Interval for Order Values
Scenario An e-commerce firm wants a 95% confidence interval for the average order value but only has a single historical sample of order amounts. Ques...
Identify Bugs in Python Script for User Assignment
Scenario A simple Python script assigns users to experiment groups and triggers the free-trial offer. Question Inspect the script and list any bugs or...
Implement Data Structure for Top-K Elements in Streams
Scenario Analytics feature that must constantly report the K largest numbers seen so far. Question Implement a data structure that ingests a stream of...
Implement Function to Return First n Prime Numbers
Scenario Quick algorithm screen to gauge Python fluency. Question Implement a Python function that returns the first n prime numbers. Hints An optimiz...
Determine Most Frequent Product Color in Carts
Scenario Online store wants to know which color of product appears most frequently in customers’ carts. Question Implement a function getMaxColor(colo...
Implement Stratified Sampling by Country
You are given a large in-memory Python list named records, where each element is a dictionary with at least the following keys: - country: str - devic...
Implement KNN from Scratch
Implement a k-nearest neighbors (KNN) classifier from scratch in Python without using scikit-learn's KNN implementation. Given training features X_tra...
Count Same-Day Registered Posters
You are given two tables: `text users - user_id: unique identifier for a user - registered_at: timestamp when the user registered posts - post_id: uni...
Maximize profit from one stock trade
Problem You are given an integer array prices where prices[i] is the price of a stock on day i. You may complete at most one transaction: choose a day...
Find Minimum Path Sum in Integer Triangle
Scenario Tech interview round 1 – dynamic programming challenge Question Given a triangle of integers, find the minimum path sum from top to bottom. A...
Determine Maximum Path Length in Directed Acyclic Graph
Scenario A backend service represents task dependencies as a directed graph; you need to understand how deep the longest dependency chain can get. Que...
Design Algorithm for Longest Substring with K Distinct Characters
Scenario Tech interview round 2 – sliding-window algorithm Question Design an algorithm that finds the length of the longest substring containing at m...
Decode and Explain Ambiguity in Compression Strings
Scenario Compression library that encodes an array as count-value pairs where value is one digit but count may be many digits. Question Implement deco...
Determine Circle Intersection Status for Rendering Order
Scenario Graphics engine must evaluate multiple pairs of circles to decide rendering order based on intersection. Question Given an array where each e...
Design Efficient Multi-Level Access Control System
Scenario Multi-level access control lists (country → city) must be queried quickly. Question Design and implement a permission system where each geogr...
Maximize Non-Overlapping Task Scheduling Efficiency
Scenario Job scheduler on a single machine wants to maximise throughput. Question Given tasks with [start, end) times, return the maximum number of no...
Maximize Stock Trading Profits Using Dynamic Programming
Scenario Evaluating dynamic-programming skills on stock-trading profits. Question Given an array of daily stock prices and an integer K, write Python ...