Senior+ Data Scientist Interview Questions
Senior+ data scientist interviews go deep on experimentation and inference, not just SQL and modeling basics. These questions were reported by candidates interviewing for senior+ DS roles, so they reflect what senior+ loops actually push on: A/B test design and analysis, causal inference when you can't run a clean experiment, metric definition and ownership, and the product judgment to turn an analysis into a decision. At the senior+ level interviewers also probe how you think about ML systems end to end — framing, evaluation, and the trade-offs behind a model in production — and how you influence stakeholders with a result. There are 70+ real, recently reported senior+ data scientist questions here across experimentation, statistics, SQL, ML, and case rounds. Most come with a detailed solution or strong-answer guidance so you can calibrate to the senior+ bar.

"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."
Demonstrate leadership in data-driven scenarios
Behavioral & Leadership Prompts for a Data Scientist (Onsite) Instructions: - Answer each prompt with a specific story using the STAR structure (Situa...
Compute 30-day power users and 7-day retention
Compute 30-day power users and 7-day retention You are interviewing for a Product/Risk Data Scientist role at a crypto exchange. Assume all timestamps...
Find maximum follow depth using recursion
You are given a directed follows relationship representing a social graph: - Each record (follower_id, followee_id) means follower_id follows followee...
Design end-to-end regression for energy demand
End-to-End Daily Energy Prediction for Commercial Buildings Context You are asked to design and justify an end-to-end regression system that predicts ...
Demonstrate leadership under disagreement
Behavioral: Disagreeing on a Launch Under Deadline (Data Scientist) You are a Data Scientist interviewing onsite for a behavioral and leadership round...
Calculate A/B sample size, CI, decision rules
A/B Test Design and Analysis: Signup Funnel You are designing and analyzing a two-arm A/B test for a signup funnel. Assume 1:1 traffic split and indep...
Implement Streaming Clustering for Numbers
You receive a continuous stream of numeric values. Choose an appropriate clustering algorithm and implement it so that each incoming number can be ass...
Find the Next Larger Palindrome
Given a positive integer n, return the smallest integer strictly greater than n whose decimal representation is a palindrome. A palindrome reads the s...
Write an average-income function
This question evaluates proficiency in data manipulation and basic statistical aggregation, particularly handling missing values and computing average...
Describe challenge, influence, and mentorship outcomes
Answer three parts using the STAR method and concrete metrics: (1) Most challenging project: what was the goal, constraints, and your specific ownersh...
Analyze omitted-variable bias in regression
Omitted-Variable Bias, Heteroscedasticity, and Remedies Setup - True data-generating process (DGP): Y = β0 + β1·Temp + β2·Occupancy + ε - Assumption...
Explain your top strengths concretely
Behavioral Prompt: Strengths, STAR Evidence, and 90-Day Application Instructions State your top one or two strengths most relevant to a Senior Data Sc...
Diagnose zero IE uploads with SQL
On 2025‑09‑01 ('today'), the dashboard shows image uploads for Internet Explorer (IE) dropped to zero. Write SQL to (a) determine if this is a technic...
Describe something you did to be inclusive
Describe something you did to be inclusive Behavioral: Inclusiveness Tell me about a time you did something to make your team or workplace more inclus...
Describe Overcoming Ambiguity and Building Cross-Team Collaboration
Describe Overcoming Ambiguity and Building Cross-Team Collaboration Behavioral & Leadership Interview — Senior Data Scientist (IC5) Context You are in...
Prove high-quality pixels improve ad performance
Prove high-quality pixels improve ad performance evaluates metric design, causal reasoning, experiment setup, diagnostics, SQL/statistical checks, and...
Write SQL for influence score and follower growth
You are working on a social product with these tables: Tables / Schemas users - user_id BIGINT (PK) - created_at TIMESTAMP posts - post_id BIGINT (PK)...
Implement Fibonacci with efficiency constraints
Write a function fib(n) that returns the nth Fibonacci number (0-indexed: fib(0)=0, fib(1)=1). Requirements: - Handle n up to at least 10^6. - Discuss...
How would you analyze retail volume drop?
Retail BTC volatility is high, but retail trading volume on Coinbase has decreased. Explain how you would investigate the issue with data and turn the...
Design metrics to detect harmful content and fraud
This interview question evaluates metric design, causal reasoning, experiment setup, diagnostics, SQL/statistical checks, and recommendations in a rea...