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."
Evaluate Fresh Content and Video Experiments
Pinterest wants to improve the perceived freshness and engagement of the home feed. Answer the following interview questions: 1. Define a practical me...
Compute Theme Similarity
This question evaluates understanding of set-based similarity metrics (the Jaccard coefficient) and practical coding skills for transforming and compa...
Describe a challenging project
You are interviewing for an L5 Data Scientist role. Answer the following behavioral questions in a way that demonstrates Deliver Results: 1. Tell me a...
Analyze Pirated Theme Usage
This question evaluates competency in temporal data manipulation, interval-overlap logic, aggregations and joins to calculate monthly usage metrics an...
Estimate impact without experiments and pick variant
Part A — Measuring impact when you cannot run an experiment You are a Staff Data Scientist working on a product change (feature/policy/model update). ...
Design and Monitor a Multi-Country Parameter Experiment
Prepare for experimentation questions spanning sample size, duration, variance reduction, multi-arm parameter tuning, sequential monitoring, and cross...
How would you use propensity score matching here
You want to estimate the causal effect of a new recommender feature on 7-day retention. The feature was not randomized: users “opt in” after seeing a ...
Can bootstrap help reduce variance
An interviewer asks: “Can bootstrap help reduce variance?” Answer this question precisely. Distinguish between: 1) Using the bootstrap to estimate var...
How to validate production models?
This question evaluates a candidate's competency in production model validation, covering model risk assessment, data and label quality, time-dependen...
Diagnose Flight Delays and Burger Launch
This question evaluates a data scientist's skills in data auditing and cleaning, feature engineering and modeling decisions (regression versus classif...
Correct length-biased sampling from family-size survey
In a town, you visit a school and ask 100 kids: “How many children are in your family?” You observe: - 50 kids say their family has 1 child - 20 kids ...
Describe influencing without authority
Behavioral (STAR) Prompt: Disagreeing With a Senior Engineer's Design Without Authority Context You are interviewing for a Data Scientist role in an o...
Assess Amazon Leadership Principles in Behavioral Interviews
Assess Amazon Leadership Principles in Behavioral Interviews Scenario Amazon Data Scientist (often L5) onsite — the Leadership Principles (LP) behavio...
Investigate marketplace metrics and experiment rollout
You are interviewing for a Senior Data Scientist role at a two-sided marketplace like Instacart, where customers place delivery orders and shoppers ch...
Query departments and top earners
This question evaluates proficiency in relational data manipulation, including multi-table joins, grouping and aggregation to identify departments wit...
Diagnose a dip in approval/conversion rate
You are a Staff Data Scientist analyzing a time series metric for a payments/fintech product. Data: Daily (or weekly) time series from Jan 2013 to Jan...
Compute Optimal Die Re-roll Strategy
This question evaluates a candidate's understanding of optimal stopping, expected-value computation, and decision-making under uncertainty in probabil...
Build House Price Model Responsibly
This question evaluates a data scientist's competencies in end-to-end supervised learning pipeline design—covering train/validation/test strategy, tar...
How do you resolve stakeholder conflict?
For a Staff Data Scientist role, describe how you work with cross-functional partners such as product managers, engineers, and business leaders. Give ...
Deliver a crisp self-introduction
90-Second Self-Introduction: Senior Data Scientist (Figma) Context You are preparing for an HR screen (behavioral/leadership) for a Senior Data Scient...