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."
Build referral chains and detect cycles
You are given a directed referral graph where each user may have at most one referrer. Input file 'referrals.csv' has columns: user_id (INT), referred...
Merge two sorted linked lists
This question evaluates proficiency with linked list data structures, pointer manipulation, in-place merging concepts, and algorithmic efficiency with...
Reverse linked lists, including k-group
Singly Linked List Reversal — Variants and Edge Cases You are given a standard singly linked list with nodes of the form: - Node fields: value, next -...
Optimize bread-factory pipeline for max profit
You can assemble a production line by choosing modules of three types: Mixers, Ovens, Packers. Each module i has (type, build_cost_i, throughput_i uni...
Implement sampling and subarray algorithms
Solve uniform 2D square sampling and longest increasing contiguous subarray. The solution maps Uniform(0,1) to Uniform(-1,1), proves uniformity by ind...
Choose fastest way to transfer 2 TB
You need to transfer a 2 TB dataset to someone located in San Francisco as fast as possible. - What transfer method(s) would you choose and why? - St...
Merge two sorted lists
This question evaluates a candidate's competency in array manipulation and merging algorithms, emphasizing understanding of ordered data and time comp...
Merge Two Sorted Lists
This question evaluates proficiency with linked list data structures, pointer manipulation, in-place merging of sorted sequences, and general algorith...
Evaluate Piecewise Linear Function
This question evaluates understanding of piecewise linear interpolation, numerical reasoning, and the ability to handle ordered 2D point data and edge...
Design robust group size limiting for calls
Design the admission-control and enforcement algorithm to limit group-call size under real-world race conditions. Constraints: multiple SFU edges in m...
Implement streaming SRM detector with late events
Implement a streaming detector for sample ratio mismatch (SRM) across many concurrent experiments. Input is two topic-partitioned streams: assignments...
Optimize switching puzzle solution
Consider a switching puzzle on an m×n grid of lights where toggling a cell flips its state and that of its orthogonal neighbors (Lights Out variant). ...
Compare two programs for equivalence
You are given two short programs (or functions) that process an integer array A (|A| ≤ 10^ 5). Determine whether they are functionally equivalent for ...
Critique Shell Script for Credit-Card Program Tech Round
Critique Shell Script for Credit-Card Program Tech Round Scenario Tech round for a new credit-card program: candidate is shown a 5-6 line shell script...
Analyze Python Functions: Improve Readability and Efficiency
Analyze Python Functions: Improve Readability and Efficiency Scenario Zoom interview code-review segment: interviewer shares three short Python functi...
Solve two string DP/hash problems
Solve the following two coding questions. 1) Unique Morse Code Transformations You are given an array of strings words (lowercase English letters). Us...
Compute Score Difference in Reversing Array Game
This question evaluates array manipulation and stateful simulation skills, parity-based control flow reasoning, and the ability to analyze time comple...
Design late-tolerant streaming window aggregator
You receive an unbounded stream of events: (event_time, user_id, category). Events may arrive up to 48 hours late and are not ordered by time. Design ...
Design and explain robust web APIs for ML inference
Design an HTTP API for Image-Based Model Predictions Context: Design an HTTP REST API that serves predictions for image inputs (e.g., classification, ...
Implement FizzBuzz
This question evaluates basic programming and algorithmic reasoning, including control flow, modular arithmetic, string handling, and the ability to a...