Tech Interview Questions

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Machine Learning Engineer + Data Scientist + Software Engineer Interview Questions

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9.2k Questions 486 Companies08.11.2026
Showing 20 results
Role
Roku logo
Roku
Medium
Data Scientist

Measure speaker impact without A/B testing

Your company launched an optional smart speaker on 2025-01-10. Adoption is voluntary; 6% of existing app users purchase within 60 days, and you cannot...

Analytics & Experimentation
8
0
77 people solved
Oct 13, 2025
Gemini logo
Gemini
Medium
Data Scientist

Design offline backtest and online experiment

You are given an ACH transaction-level dataset to identify and control fraud and will present a plan. Today is 2025-09-01. Deliverables - Offline anal...

Analytics & Experimentation
3
0
45 people solved
Oct 13, 2025
Gemini logo
Gemini
Medium
Data Scientist

Compute power and cost-aware thresholds

You are evaluating a new ACH velocity+shared-device block rule. Assumptions - Volume: 1,000,000 ACH credits/month. - Baseline fraud prevalence: 0.15% ...

Statistics & Math
5
0
66 people solved
Oct 13, 2025
Gemini logo
Gemini
Medium
Data Scientist

Lead a cross-team fraud incident response

Describe a specific time you led a high-severity ACH fraud incident from detection to resolution. Include: (1) the first on-call signal you saw, (2) t...

Behavioral & Leadership
2
0
34 people solved
Oct 13, 2025
Meta logo
Meta
Medium
Data Scientist

Compute cohort GMV and payer rate with edge cases

You are given the following schema (timestamps are UTC): users(user_id INT, country STRING, created_at TIMESTAMP) events(user_id INT, event_ts TIMESTA...

Data Manipulation (SQL/Python)
10
0
82 people solved
Oct 13, 2025
Meta logo
Meta
Medium
Data Scientist

Estimate shuttle impact with robust causal design

You have individual-level data from 1,000+ sites, several hundred of which adopt a free employee shuttle at different times. Design a causal analysis ...

Analytics & Experimentation
2
0
36 people solved
Oct 13, 2025
Meta logo
Meta
Medium
Data Scientist

Resolve a team conflict decisively

Tell me about a time you resolved a significant conflict within a team under time pressure. Include: 1) the root causes (interests, incentives, commun...

Behavioral & Leadership
3
0
27 people solved
Oct 13, 2025
Meta logo
Meta
Medium
Data Scientist

Compute video-call SQL metrics with edge cases

Use 'today' = 2025-09-01. Assume UTC timestamps. Write SQL to answer both parts below and call out how your queries handle edge cases (duplicates, fai...

Data Manipulation (SQL/Python)
29
1
242 people solved
Oct 13, 2025
Meta logo
Meta
Medium
Data Scientist

Compute unconnected 60s posts and reactions averages

Given these tables and sample data, write SQL that answers both tasks below. Use today = 2025-09-01 and interpret "last/past 7 days" as the inclusive ...

Data Manipulation (SQL/Python)
1
0
11 people solved
Oct 13, 2025
Amazon logo
Amazon
Hard
Data Scientist

Quantify build-vs-buy training decision

Quantitative Decision Framework for Selecting a New Employee Training Program Context Your company must choose one of three ways to launch a new emplo...

Analytics & Experimentation
2
0
35 people solved
Oct 13, 2025
Capital One logo
Capital One
Medium
Data Scientist

Map stakeholders and influence routes

Behavioral Scenario: Coordinating Multiple Recruiters Across Teams (Data Scientist, Onsite) Context You're at the onsite stage for a Data Scientist ro...

Behavioral & Leadership
1
0
21 people solved
Oct 13, 2025
Capital One logo
Capital One
Medium
Data Scientist

Draft a non-pushy follow-up email

Follow-Up Email After Team-Match (3 Business Days) Context: You are a candidate for a Data Scientist role. Three business days after an onsite team-ma...

Behavioral & Leadership
3
0
45 people solved
Oct 13, 2025
Meta logo
Meta
Medium
Data Scientist

Write SQL for visibility, calls, and cohort activity

You have the following schema and toy data. Assume "today" = 2025-09-01. users(user_id INT, signup_date DATE) Sample: user_id | signup_date -------...

Data Manipulation (SQL/Python)
1
0
8 people solved
Oct 13, 2025
Amazon logo
Amazon
Medium
Data Scientist

Compute array modes with ties and no-mode rule

Write a function that returns the mode(s) of an integer array. Requirements: if all values are unique, return an empty list (there is no mode); allow ...

Coding & Algorithms
3
0
32 people solved
Oct 13, 2025
Meta logo
Meta
Medium
Data Scientist

Design a clustered notification experiment with guardrails

You work on a mobile travel app (think TripAdvisor-like) that will test a new push-notification policy recommending nearby attractions. Design a rigor...

Analytics & Experimentation
2
0
36 people solved
Oct 13, 2025
Capital One logo
Capital One
Medium
Data Scientist

Evaluate ROI and payback for renewables

You’re advising NorthGrid Energy on a utility-scale renewables investment with the following Year-1 economics unless noted: upfront capex = $50,000,00...

Statistics & Math
6
0
58 people solved
Oct 13, 2025
Meta logo
Meta
Medium
Data Scientist

Characterize metric distribution and quantiles

KPI Analysis: Per-Video Watch Time (seconds) You are evaluating a pilot dataset for the KPI "per‑video watch time" (in seconds). The dataset (n = 20) ...

Statistics & Math
1
0
36 people solved
Oct 13, 2025
Meta logo
Meta
Hard
Data Scientist Locked

Choose KPIs for short-video recommendations

This question evaluates a data scientist's ability to define precise product metrics, set guardrails, design and power A/B tests, and apply weighted d...

Analytics & Experimentation
3
0
25 people solved
Oct 13, 2025
Meta logo
Meta
Medium
Data Scientist

Write SQL for retention, conversion, and churn

Assume today is 2025-09-01 (use the user's local day boundaries based on users.tz). Given the following schema and sample data, write SQL to: (a) Comp...

Data Manipulation (SQL/Python)
12
0
127 people solved
Oct 13, 2025
Medium
Data Scientist

Write SQL to analyze response accuracy and speed

You are given response-level data for an online assessment with sections verbal/design/analytics and verbal subtypes grammar/vocab/tense/other. Using ...

Data Manipulation (SQL/Python)
1
0
33 people solved
Oct 13, 2025