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
Easy
Software Engineer

Find largest digit-sharing subset

You are given an array of N integers. Each integer has exactly two decimal digits (i.e., each element is between 10 and 99 inclusive). You want to cho...

Coding & Algorithms
10
0
112 people solved
Dec 8, 2025
Google logo
Google
Easy
Software Engineer

Maximize coins with tokens moving by +3

You are given a 1D board represented by a string s of length n. Each character is one of: - '.' — an empty cell - 'C' — a cell containing exactly one ...

Coding & Algorithms
21
2
203 people solved
Dec 5, 2025
Google logo
Google
Medium
Data ScientistSenior+

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...

Coding & Algorithms
6
0
56 people solved
Nov 24, 2025
Google logo
Google
Hard
Software Engineer

Count same-color squares in a character grid

You are given a 2D grid (matrix) of characters. Each character represents a color: cells with the same character are considered the same color. Formal...

Coding & Algorithms
13
1
157 people solved
Nov 22, 2025
Google logo
Google
Medium
Software Engineer

Find mode in a trinary search tree

You are given the root of a trinary search tree where each node has up to three children: `text class Node { int val; Node left; // all values ...

Coding & Algorithms
12
0
135 people solved
Nov 16, 2025
Google logo
Google
Medium
Software Engineer

Compute servers needed for daily recurring jobs

You operate a cluster of identical servers that run recurring daily jobs. For a single day, you are given a list of job execution intervals. Each inte...

Coding & Algorithms
15
0
144 people solved
Nov 5, 2025
Google logo
Google
Medium
Software Engineer

Minimize calls to find all bad test pairs

You have \(n\) atomic tests \(t_1, t_2, \dots, t_n\). You are given access to a black-box function: `python bool runTest(set<Test> S) ` which behaves ...

Coding & Algorithms
13
0
140 people solved
Nov 5, 2025
Google logo
Google
Medium
Software Engineer

Find shared objects across two log files

You are given two large log files representing activity on two different days. Each line of each log has three fields: - timestamp: a time value (you ...

Coding & Algorithms
6
0
79 people solved
Nov 5, 2025
Google logo
Google
Easy
Software Engineer

Find right-side view of binary tree

You are given the root of a binary tree. From the right side of the tree, at each depth you can see exactly one node: the rightmost node at that depth...

Coding & Algorithms
6
0
63 people solved
Nov 1, 2025
Google logo
Google
Easy
Data Scientist

Match payments to invoices by memo or amount

Scenario You are building a small reconciliation tool that matches payments to invoices. Data structures Assume you are given: - invoices: a list of i...

Coding & Algorithms
8
0
57 people solved
Oct 25, 2025
Google logo
Google
Medium
Data Scientist

Match payments to invoices by memo or amount

You are building a small payment-to-invoice matching utility. Data You are given: - invoices: a list of invoice records with: - invoice_id (string) ...

Coding & Algorithms
5
0
51 people solved
Oct 19, 2025
Google logo
Google
Easy
Software Engineer

Compute max coins with 3-step token moves

You are given a one-dimensional board with n positions represented by a string s of length n: - . = empty cell - T = token - C = coin You may move tok...

Coding & Algorithms
22
0
151 people solved
Oct 16, 2025
Google logo
Google
Medium
Data Scientist

Implement percentage RMSE and bootstrap its CI

Given a CSV with columns [country, actual_revenue, predicted_revenue], define percentage RMSE as pRMSE = sqrt(mean_i((pred_i/actual_i − 1)^2)). a) Imp...

Coding & Algorithms
6
0
49 people solved
Oct 13, 2025
Google logo
Google
Medium
Data Scientist

Generate binomial matrix and column-normalize

Using Python with NumPy, generate a 100×100 matrix of Binomial(n = 10, p = 0.3) draws with a fixed random seed, then normalize each column so it sums ...

Data Manipulation (SQL/Python)
0
0
5 people solved
Oct 13, 2025
Google logo
Google
Medium
Data Scientist

Analyze video flags and reviews with SQL

You are designing SQL queries for YouTube Trust & Safety. Use the schema and sample data below. Unless stated otherwise, treat a flag as reviewed if t...

Data Manipulation (SQL/Python)
28
2
244 people solved
Oct 13, 2025
Google logo
Google
Medium
Data Scientist

Write SQL/Python for messy event data

Using the schema and sample data below, write: (1) a single SQL query to compute daily metrics for the local date 2025-09-01 in America/Los_Angeles, a...

Data Manipulation (SQL/Python)
3
0
27 people solved
Oct 13, 2025
Google logo
Google
Medium
Data Scientist

Add a conditional column in Python

Using pandas, add a derived column to a table based on multiple conditions with strict precedence and missing-value handling. Given the sample DataFra...

Data Manipulation (SQL/Python)
0
0
5 people solved
Oct 13, 2025
Google logo
Google
Medium
Data Scientist

Implement longest subarray summing to k

Given an integer array nums (length ≤ 200,000; values may be negative) and integer k, return the maximum length and the [l, r] indices of a contiguous...

Coding & Algorithms
8
0
68 people solved
Oct 13, 2025
Google logo
Google
Medium
Data Scientist

Compute monthly CRR with merges and gaps

You are given PostgreSQL tables user_profile(user_id, signup_ts, country, is_employee, is_test), user_events(user_id, event_ts, event_type, revenue, p...

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

Deduplicate events and rank products with SQL

You are given two tables. Schema: - events(event_id INT PRIMARY KEY, user_id INT, product_id INT, event_time TIMESTAMP, idempotency_key TEXT, amount_c...

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