Reddit 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."
"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."
Design a game leaderboard service
System Design: Game Leaderboard Design a backend service that powers leaderboards for an online game. Core functionality - Players submit score update...
Design a video recommendation system
Scenario You are designing an ML-driven video recommendation product (home feed + “up next”) for a consumer app. The interviewer focuses heavily on in...
Design A/B test for AI chat box
Context A social platform (e.g., Reddit) plans to launch an AI chat box that answers user questions. The functionality overlaps with the existing Sear...
Implement a sliding-window rate limiter
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Find word sequence with 1–2 char changes
Given a beginWord, an endWord, and a dictionary (wordList) of unique same-length lowercase words, determine whether there exists a transformation sequ...
Measure impact of ads-manager automation feature
Context An Ads Manager product has new automation features (e.g., auto-bidding, auto-budgeting, auto-creative suggestions). You need to measure the fe...
Design comment-likelihood prediction platform
Scenario You’re building an ML platform component that serves a model to predict the likelihood that a user will comment on a given post. The intervie...
Build and evaluate click prediction models
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Design a feature store with CI/CD and reliability
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Collaborate with PM and Eng as DS
Question As a Data Scientist working with Product Managers and Engineers: 1. How do you structure collaboration (requirements, timelines, ownership)? ...
Query US-based users and most active forums
You are given user and post data for an online forum platform. Tables (schemas) Assume the following tables: users - user_id BIGINT (PK) - home_countr...
Justify synthetic control and handle inference
Synthetic Control: Assumptions, Estimation, Inference, and Diagnostics Context You are estimating the causal effect of an intervention on a single tre...
Design a causal evaluation without A/B testing
Non-Randomized Launch Decision via Synthetic Control: Complete Analysis Plan You need to make a go/no-go decision for a high-impact feature that canno...
Design experiment for ads in chat with budgets
Context After launching an AI chat feature, the company wants to show ads inside the chat experience (you are interviewing for an Ads/Monetization dat...
Prioritize competing engineering requests
Scenario You are a Data Scientist/Analytics partner supporting multiple engineering teams. Two (or more) teams simultaneously ask you to prioritize th...
Communicate and de-risk a non-experimental launch
Decision-to-Launch Plan After a Synthetic Control Result Context You are a data scientist who used a Synthetic Control method to estimate the causal i...
Compute P(A>B) for m- and n-sided dice
Two fair dice are rolled independently: - Die A has m faces labeled \(1,2,\dots,m\). - Die B has n faces labeled \(1,2,\dots,n\). Each face is equally...
Model y from x and interpret distributions
Scenario You are given a dataset with one input feature x and a target y. The interviewer asks: “How would you model this?” Later, you are shown a plo...
Describe a failure and a success
Questions 1. Tell me about a time you failed (or something didn’t go as planned). What happened, what did you learn, and what would you do differently...
Load and prepare JSON for modeling
Using Python in a Jupyter notebook, load a JSON dataset with fields: ( 1) hours spent reading A posts (float), ( 2) hours spent reading B posts (float...