Google Coding Interview Questions (2026 Guide)

By DSA Prep Team · February 15, 2026 · 15 min read · Data: 500 verified questions
Google interviews are not about memorizing answers ā€” they're about demonstrating you can think at scale. Brute force is just the starting point. The real question is always: can you do better?

This guide breaks down 500 real Google interview questions: which patterns dominate, the exact difficulty mix, the top 20 problems you should solve, and a focused 30-day plan to get you there.

šŸ“‹ Table of Contents

Overview: What Google Actually Asks

Based on 500 real interview questions from Google, here's what you need to know:

Difficulty Breakdown:

Easy:   28%  (140 questions)
Medium: 53%  (265 questions)
Hard:   19%  (95 questions)

šŸ’” Key Insight

Google has the highest Hard % among FAANG at 19%. Unlike Amazon or Meta, Google regularly pushes into hard territory ā€” especially in later rounds. Don't skip hard problems in your prep.

Top 10 Patterns Asked at Google

RankPatternFrequencyQuestions
1Array51.2%256
2String22.6%113
3Hash Table19.8%99
4Dynamic Programming16.4%82
5Two Pointers15.0%75
6Math14.4%72
7Sorting10.8%54
8Binary Search9.6%48
9Depth-First Search8.8%44
10Matrix8.6%43

Pattern Strategy

Top 20 Google Interview Questions

The most frequently asked and recent problems from Google, grouped by difficulty:

šŸŸ¢ Easy

#ProblemPatternsLink
1 Two Sum Array, Hash Table LeetCode ā†’
2 Palindrome Number Math LeetCode ā†’
3 Best Time to Buy and Sell Stock Array, Dynamic Programming LeetCode ā†’
4 Longest Common Prefix String, Trie LeetCode ā†’
5 Roman to Integer Hash Table, Math, String LeetCode ā†’
6 Valid Parentheses String, Stack LeetCode ā†’
7 Single Number Array, Bit Manipulation LeetCode ā†’

šŸŸ” Medium

#ProblemPatternsLink
1 Add Two Numbers Linked List, Math, Recursion LeetCode ā†’
2 Longest Consecutive Sequence Array, Hash Table, Union Find LeetCode ā†’
3 Longest Substring Without Repeating Characters Hash Table, String, Sliding Window LeetCode ā†’
4 Merge Intervals Array, Sorting LeetCode ā†’
5 3Sum Array, Two Pointers, Sorting LeetCode ā†’
6 4Sum Array, Two Pointers, Sorting LeetCode ā†’
7 Zigzag Conversion String LeetCode ā†’
8 Top K Frequent Words Hash Table, String, Trie LeetCode ā†’
9 Container With Most Water Array, Two Pointers, Greedy LeetCode ā†’
10 Next Permutation Array, Two Pointers LeetCode ā†’

šŸ”“ Hard

#ProblemPatternsLink
1 Trapping Rain Water Array, Two Pointers, DP LeetCode ā†’
2 Median of Two Sorted Arrays Array, Binary Search, Divide and Conquer LeetCode ā†’

30-Day Google Prep Plan

Week 1ā€“2 Core Patterns (Focus on Top 3)

Week 3 Mixed Difficulty Practice

Week 4 Mock Interviews & Hard Problems

Self-Assessment ā€” by end of Week 4 you should:

What Makes Google Interviews Unique

āš” Optimization is the Expectation

Brute force is just the starting point at Google. Interviewers expect you to optimize without being prompted. If you stop at O(nĀ²), they'll push you to O(n log n) or O(n). Know your next step before they ask.

šŸ“ Complexity Analysis is Non-Negotiable

Be completely fluent in Big-O notation. Google interviewers discuss time/space trade-offs as naturally as the solution itself. Fumbling on complexity is a red flag even for otherwise good solutions.

šŸ” Googleyness: Curiosity + Clarity

Show genuine curiosity ā€” ask clarifying questions upfront, think about edge cases proactively, and consider scalability before being asked. Interviewers reward structured, forward-thinking communication.

šŸ—‚ļø Present Multiple Solutions

Google values breadth and depth. Walk through 2ā€“3 approaches (brute force ā†’ optimized ā†’ best). Even if you don't fully implement all of them, showing the thought process earns significant credit.

How to Track Your Google Prep with DSAPrep.dev

DSAPrep.dev Google filter view

Step 1: Filter by Company

Step 2: Track Pattern Coverage

Step 3: Schedule Reviews

Step 4: Mock Interview Mode

DSAPrep.dev leetcode spaced repetition tracker dashboard

Common Mistakes in Google Prep

āš ļø Mistake 1: Only Solving Google-Tagged Problems

Why it fails: LeetCode company tags are often incomplete or outdated.

Better: Learn the patterns Google favors, then solve ANY problem in those patterns. Pattern fluency > memorizing specific questions.

āš ļø Mistake 2: Stopping at the First Working Solution

Why it fails: Google interviewers are specifically evaluating whether you push further. A correct but unoptimized answer often doesn't pass.

Better: After every solution, immediately ask yourself: "Can I reduce time complexity? Can I reduce space? Is there an O(n) approach?"

āš ļø Mistake 3: No Spaced Repetition

Why it fails: You solve 50 problems but forget 40 by interview day.

Better: Review problems 3ā€“5 times over 2ā€“4 weeks. DSAPrep.dev automates this scheduling for you.

Conclusion: Your Google Interview Roadmap

Today

This Week

This Month

šŸš€ Start Today

You'll recognize patterns in seconds. You'll optimize without being prompted. You'll pass because you prepared strategically ā€” not randomly.

ā†’ Start Tracking Google Prep on DSAPrep.dev (Free)
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