Google Interview Questions

Google Coding & Algorithms Interview Questions

Practice 514 real Google interview questions for 2026. Covers Coding & Algorithms, Behavioral & Leadership, Analytics & Experimentation, Machine Learning, and System Design across Software Engineer, Data Scientist, Machine Learning Engineer, Product Manager, and Data Engineer roles — real questions from actual interviews with detailed solutions to accelerate interview preparation. This collection highlights the coding-first bar Google uses: expect heavy algorithmic work, role-related data and ML problems, a Googleyness/leadership round, and level-specific differences in what’s decisive. What’s distinctive: for Software Engineers you’ll see spatial and streaming algorithms, concurrency and async primitives, LLM-foundations and GPU-job scheduling, plus object-design problems like room assignment; Data Scientists are weighted toward causal experiments, funnel and product-metric diagnostics, bootstrap inference, and percentile/sampling algorithms; ML Engineers focus on transformer blocks, recommendation design and ranking cold-starts; PMs get Maps/Android and product-ideation tradeoffs plus throughput and revenue sizing. New-grad and intern tracks emphasize phone screens and virtual onsites; Google L4 typically keeps the loop coding-heavy while Google L5 expects stronger system-design and cross-team leadership signals. Use focused practice, mock interviews, and level-specific stories to prepare.

514 Questions 1 Company08.01.2026
Showing 20 results
Role
Google logo
Google
Hard
Data Scientist Locked

Explain Bootstrap and Statistical Inference

This question evaluates a data scientist's competence with resampling methods (bootstrap), uncertainty quantification and hypothesis testing (variance...

Statistics & Math
42
0
299 people solved
Dec 29, 2025
Google logo
Google
Medium
Software Engineer

Filter Repeated Robot Status Messages

Filter Repeated Robot Status Messages Implement filter_messages(events) for a robot status stream. Each event is a pair [timestamp, message]. Return, ...

Coding & Algorithms
6
1
24 people solved
Jul 5, 2026
Google logo
Google
Easy
Data Scientist

Select MOST/LEAST appropriate actions (SJT)

Situational Judgment Test (SJT): Choose the MOST and LEAST appropriate action This question reproduces the format of a pre-interview Situational Judgm...

Behavioral & Leadership
36
0
539 people solved
Dec 2, 2025
Google logo
Google
Hard
Software Engineer Locked

Design a pub-sub replay system

This question evaluates a candidate's skills in distributed systems and streaming architectures, including pub-sub replay semantics, message ordering,...

System Design
24
0
455 people solved
Mar 6, 2026
Google logo
Google
Medium
Software EngineerNew Grad

Design a restaurant waitlist system

You are implementing the waitlist system for a restaurant. Parties arrive over time, can cancel, and get seated when a table becomes available. Rules ...

Coding & Algorithms
109
2
1266 people solved
Mar 1, 2026
Google logo
Google
Medium
Machine Learning Engineer Locked

Design an app-store app recommendation system

This question evaluates a candidate's competency in end-to-end machine learning system design for recommender systems, covering personalization, candi...

ML System Design
10
0
200 people solved
Feb 11, 2026
Google logo
Google
Easy
Software Engineer Locked

Busiest Rental Car

This question evaluates a candidate's ability to simulate a resource-allocation process using interval scheduling and greedy assignment rules. It test...

Coding & Algorithms
5
0
18 people solved
Jun 22, 2026
Google logo
Google
Medium
Software Engineer

Choose Your Workplace Style

You are taking a forced-choice workplace-style assessment for a Software Engineer role. Each item contains three positive statements. For each item: 1...

Behavioral & Leadership
13
0
114 people solved
Apr 12, 2026
Google logo
Google
Medium
Software Engineer

Solve chat, grid paths, and car rentals

You are given three independent programming tasks. For each, describe and implement an efficient algorithm, and be prepared to analyze its time and sp...

Coding & Algorithms
14
0
190 people solved
Dec 2, 2025
Google logo
Google
Medium
Data ScientistSenior+

When do you use mixed-effects models

You are modeling a user outcome (e.g., watch time or retention) across many countries and many users. Observations are nested (multiple days per user;...

Machine Learning
19
0
201 people solved
Nov 24, 2025
Google logo
Google
Hard
Software EngineerSenior+

Plan a Safe Repository-Wide Identifier Migration

Plan a Safe Repository-Wide Identifier Migration You have a very large repository whose internal variables and function names use snake case. A conver...

Software Engineering Fundamentals
3
0
25 people solved
Apr 16, 2026
Google logo
Google
Medium
Software Engineer

Solve three coding interview problems

You are given three independent coding questions. 1) Decode an encoded string Given an encoded string s, decode it using the following rule: - Pattern...

Coding & Algorithms
18
0
199 people solved
Oct 9, 2025
Google logo
Google
Medium
Software EngineerIntern

Describe Key Behavioral Examples

Prepare to answer behavioral questions based on past internship or project experience. Common prompts include: 1. Tell me about a time when you disagr...

Behavioral & Leadership
56
0
387 people solved
Mar 19, 2026
Google logo
Google
Hard
Software Engineer

Find maximum value in huge text file

You are given the path to a very large text file on disk. The file has the following properties: - Each line contains exactly one signed 64-bit intege...

Coding & Algorithms
31
0
225 people solved
Dec 8, 2025
Google logo
Google
Medium
Software Engineer Locked

Assign meetings to rooms with delays

This question evaluates skill in scheduling algorithms, priority queue and heap usage, greedy decision-making, and time-based event simulation for man...

Coding & Algorithms
12
1
146 people solved
Jan 6, 2026
Google logo
Google
Medium
Machine Learning Engineer

Explain LLM lifecycle and trade-offs

Explain the end-to-end lifecycle of a modern large language model. Cover training data collection and filtering, pretraining objectives, transformer a...

Machine Learning
16
1
173 people solved
Jan 19, 2026
Google logo
Google
Medium
Machine Learning Engineer Locked

Design a fraud detection system

This question evaluates a candidate's competency in designing end-to-end fraud detection machine learning systems, covering real-time and batch featur...

ML System Design
50
1
424 people solved
Jan 22, 2026
Google logo
Google
Medium
Data ScientistSenior+

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...

Statistics & Math
15
0
183 people solved
Nov 24, 2025
Google logo
Google
Medium
Software Engineer

Design an Enterprise AI Adoption Agent for a Global Company

Design an enterprise AI adoption agent for a global company with internal data, tools, and security constraints. `hint Hint 1 Start by stating assumpt...

System Design
8
0
60 people solved
Mar 6, 2026
Google logo
Google
Hard
Data Scientist Locked

Design an Unbiased Upgrade Experiment

This question evaluates understanding of causal inference, experiment design, and metric selection in product analytics, including defining causal est...

Analytics & Experimentation
18
0
133 people solved
Dec 29, 2025

Frequently Asked Questions

How hard are Google interview questions and how does difficulty vary by level?
Google interview questions are challenging but predictable: they range from medium algorithmic problems for new grads to hard, system- and architecture-focused problems at senior levels. L3/new-grad interviews emphasize correct, clean code with solid complexity and edge-case handling; expect two to three coding rounds plus a Googleyness/leadership conversation. L4 requires optimal solutions, clearer trade-off communication, and sometimes a system-design or domain round. L5 raises the bar on system design, scalability, ownership, and leadership impact. Non-SWE roles shift emphasis toward statistics, experiment design, or model-building depending on the job.
What does the Google interview process look like and where do these 514 questions appear?
The typical loop starts with a recruiter screen, one or more phone or virtual coding screens, then a virtual or in-person onsite loop of 3–5 forty-five minute interviews: mostly coding, plus a Googleyness/leadership behavioral round and usually one domain or system-design session for mid and senior roles. The 514-question corpus covers those stages: phone-screen style coding, onsite deep-coding, system-design prompts, analytics/experiment questions for data roles, ML implementation prompts, and product-spec behavioral cases. Hiring committee review, level calibration, and team match happen after the loop and extend timelines by several weeks.
How should I schedule my preparation and how much time do I need to prepare effectively?
Plan prep based on level and role: new grads should spend 4–6 weeks focused on core data structures, algorithm patterns, and 4–6 polished STAR stories. Mid-level L4 candidates should budget 6–10 weeks, adding system design and production-readiness topics plus mock interviews. L5 and above need 8–12+ weeks emphasizing architecture, trade-offs, and leadership narratives. Break weeks into coding practice, timed mocks, system-design sprints, and role-specific work (experiments for DS, model lifecycle for MLE). Run at least 6–10 realistic mock interviews and iterate on communication and edge-case testing.
What specific subtopics and recurring themes should I expect by role at Google?
For Software Engineer interviews expect spatial and streaming geometry problems (counting or removing points within distance), concurrency and async primitives, deterministic task ordering and schedulers, calendar/free-slot algorithms, boolean-expression fixes, array/subarray patterns, and small-system OOD prompts like dorm room assignment. Data Scientist questions concentrate on causal and experiment design, funnel and product-metric computation, unbiased upgrade experiments, bootstrap and percentile estimation from buckets, sampling algorithms, and applied modeling like shot-conversion. Machine Learning Engineer rounds emphasize transformer/LLM building blocks and trade-offs, recommendation and ranking cold-start strategies, weighted sampling, and implementation details.
Any standout tips and common pitfalls, including level-specific advice (L3, L4, L5) and intern/new-grad notes?
Start by matching preparation to level: L3/new-grad must deliver correct, well-tested code and clear complexity; L4 must reach optimal solutions, explain trade-offs, and show production thinking; L5 must demonstrate architecture, scaling trade-offs, and cross-team impact. For interns/new-grads expect a phone coding screen followed by a virtual onsite; practice timed screens and basic system thinking. Across levels, talk through examples, define constraints, test edge cases, and avoid premature optimization or vague assumptions. Prepare 4–6 STAR stories for Googleyness, and don’t overlook clear, testable code and thought-out system trade-offs.

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