Machine Learning Engineer + Data Scientist + Software Engineer Interview Questions
Practice the exact questions companies are asking right now.
"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."
Design a robust traffic forecasting pipeline
This question evaluates a candidate's competency in end-to-end time-series forecasting pipeline design, covering data cleaning and missing-value handl...
Optimize invites under capacity constraints
You have n donors (n up to 100,000). For each donor i you know: p_online[i] (probability of donating if emailed), a_online[i] (expected donation condi...
Write SQL to compare social-only vs game-only engagement
You are given two tables capturing Oculus app usage. Define an 'active day' as a UTC date on which a user generates at least one event. Consider only ...
Estimate Portal’s causal lift on video-call usage
This question evaluates applied causal inference and statistical analysis skills, including defining estimands, designing staggered-adoption differenc...
Assess 3.4M target and design experiments
This question evaluates skills in growth analytics, market sizing (TAM→SAM→SOM), funnel modeling, unit economics (CAC/LTV), capacity planning, and exp...
Reconcile ledgers with SQL/Python and late events
You own a daily ETL + reconciliation job between two financial ledgers. Late postings (“delay time”) up to 48 hours are common. Schema: - payments_raw...
Compute capacity, staffing trade-offs, and break-even
This question evaluates capacity-planning, bottleneck identification, labor-cost trade-offs, contractor vs overtime comparisons, break-even computatio...
Compute precision–recall curve on imbalanced data
You receive a CSV with columns: actual_label ∈ {0,1} and predicted_prob ∈ [0,1]; the positive class rate is ≈5%. a) Which evaluation metrics would you...
Minimize L2, L1, and quantile losses
Given an array X of n real numbers, derive the value θ that minimizes the sum of squared deviations Σ(xi−θ)² (mean) and the sum of absolute deviations...
Design hashtag recommender with cold start
This question evaluates expertise in recommender-system design, feature engineering, ranking and learning-to-rank models, cold-start strategies, evalu...
Compute join counts and window ranks
Given the following small schema and data, answer all parts precisely and justify each count/output. Tables and rows: Customers(cust_id INT PRIMARY KE...
Transform clickstream with pandas sessionization
Given a pandas DataFrame events with columns [user_id:int, ts:str ISO8601 or NaT, url:str, server_log_ts:datetime], build 30-minute inactivity session...
Write SQL for cohort retention and ARPU
Using PostgreSQL, compute monthly signup cohort D30 retention and 30-day ARPU. Cohort month = date_trunc('month', signup_date). D30 retention = users ...
Write left-join queries with tricky filters
Assume 'today' = '2025-09-01'. Do NOT use window functions (e.g., RANK). Use LEFT JOIN, COUNT(DISTINCT), GROUP BY, HAVING as appropriate. Schema: - us...
Find longest uniform substring after k replacements
Given a string s (ASCII, length up to 2e5) and integer k (0 ≤ k ≤ |s|), return the length of the longest substring that can be turned into all the sam...
Assess SQL joins, unions, windows, dedup, and pandas
Using the schema and sample data below, answer all sub-questions. Unless stated, assume ANSI SQL and explain any dialect-specific choices. Schema: - c...
Count buggy vs non-buggy by employer
Count buggy vs non-buggy submissions for each employer_id, including employers with zero submissions. Return employer_id, buggy_count, non_buggy_count...
Maximize products bought under budget
Given N products and M customers, for each customer find the list of distinct products they can buy without exceeding their budget such that the numbe...
Select max-discount product per category
You have a catalog of products. For each category, return exactly one product: the one with the largest absolute discount; if multiple products in the...
Write SQL to verify quarterly sales decline
You are given a single dataset for a beverage company and must decide whether Q2 2024 truly declined. Write one standard SQL query that produces a com...