Machine Coding Sheet

Google Machine Coding Interview

Top low-level design (LLD) and machine coding questions frequently asked in Google interviews. Master these to clear the LLD round.

Overall progress

0/104 solved

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easy0/18

medium0/45

hard0/41

0/104

Solved

CategoryCompanyStatus

Utility

0/4 solved

Problem	Difficulty	Key Focus
Parking Lot Asked by:AmazonGoogleMicrosoft+2 more	Easy	Inheritance, Enums, Strategy Pattern
Library Management System Asked by:AmazonMicrosoftGoogle	Easy	Search & Strategy Penalty Logic
Vending Machine Asked by:GoogleAmazonMicrosoft	Medium	State Pattern (Idle/Dispense)
Coffee Machine Asked by:GoogleAmazonMicrosoft	Medium	Decorator Pattern, State Pattern, Inventory Checks, Thread-Safe Brewing

Games

0/1 solved

Status	Star	Problem	Difficulty	Key Focus	Notes
		Tic-Tac-Toe Asked by:GoogleMicrosoftAmazon+1 more	Easy	Scalable N×N Board & Win Strategies

Infrastructure

0/13 solved

Problem	Difficulty	Key Focus
Backup Manager Asked by:AWSGoogleMicrosoft+1 more	Easy	Incrementals, RPO/RTO Logic
Elevator System Asked by:GoogleAmazonMicrosoft+1 more	Medium	State, Strategy (Dispatching)
API Rate Limiter Asked by:StripeGoogleAmazon+2 more	Medium	Token Bucket, Sliding Window
Logger Library Asked by:GoogleAmazonSplunk+1 more	Medium	Strategy Formatter & Asynchronous Composite Sinks
Notification Service Asked by:MetaAmazonApple+1 more	Medium	Factory Method, Strategy Pattern, Decorator Pattern, Rate Limiting
File System (Unix-like) Asked by:MicrosoftAppleGoogle+1 more	Medium	Composite Pattern, Concurrent Read/Write Locks, Hierarchical Path Resolution
In-Memory Cache (LRU/LFU) Asked by:RedisLabsAmazonTwitter+1 more	Medium	Strategy Pattern, Generics, Concurrent Read-Write Locks, Eviction Mechanics
A/B Testing Library Asked by:NetflixMetaOptimizely+1 more	Medium	Hashing, User Bucketing
Unit Testing Framework Asked by:JetBrainsMicrosoftGoogle	Medium	Reflection, Annotation Logic
In-Memory Key-Value Store Asked by:RedisLabsGoogleAmazon+1 more	Hard	Nested Transactions & Command Logs
Job Scheduler Asked by:GoogleAirbnbNetflix+1 more	Hard	Command & Observer Patterns, PriorityQueue, Exponential Backoff, Concurrent Locks
Package Manager Asked by:npmGitHubMicrosoft+1 more	Hard	Dependency Graph Resolution
Distributed Lock Manager Asked by:UberGoogleAmazon+1 more	Hard	Lease Management, Fencing

Fintech

0/1 solved

Status	Star	Problem	Difficulty	Key Focus	Notes
		ATM Machine Asked by:GoogleMicrosoftJPMorgan Chase	Medium	Chain of Responsibility & State Pattern

Commerce

0/2 solved

Status	Star	Problem	Difficulty	Key Focus	Notes
		Review & Rating System Asked by:YelpAmazonGoogle+1 more	Easy	Weighted Average, Spam Filter
		Price Comparison Engine Asked by:GoogleAmazonPayPal	Easy	Normalization, Entity Matching

Productivity

0/4 solved

Problem	Difficulty	Key Focus
Meeting Scheduler Asked by:MicrosoftGoogleUber+1 more	Medium	Concurrency, Interval Trees
Survey Monkey (Survey System) Asked by:QualtricsGoogleMicrosoft	Medium	Dynamic Form Modeling
Shared Calendar Asked by:GoogleMicrosoftApple	Medium	Recurring Event Expansion
Excel / Spreadsheet Engine Asked by:MicrosoftGoogleApple	Hard	Dependency Graph, Cell Eval

Search

0/3 solved

Problem	Difficulty	Key Focus
Quora (LLD) Asked by:QuoraPinterestGoogle	Medium	Topic Graph, Expertise Score
Search Ranking (Learning to Rank) Asked by:GoogleMicrosoftAmazon+1 more	Hard	NDCG, Feature Engineering
Search Engine with Trie Asked by:GoogleMicrosoftYahoo	Hard	Trie suggestions, Inverted Index, TF-IDF Strategy, Boolean Query Intersections

Geo

0/2 solved

Status	Star	Problem	Difficulty	Key Focus	Notes
		Foursquare Check-In System Asked by:AirbnbFoursquareGoogle	Easy	Venue Search, Badges
		ETA Calculator Asked by:UberLyftGoogle	Hard	Dijkstra with Live Weights

Education

0/1 solved

Status	Star	Problem	Difficulty	Key Focus	Notes
		Online Judge (LeetCode-lite) Asked by:GoogleMicrosoftHackerRank	Hard	Sandbox Strategy, Observer Pattern, Thread-Safe Judge Pool, Leaderboard Aggregation

IoT

0/1 solved

Status	Star	Problem	Difficulty	Key Focus	Notes
		Smart Home System Asked by:AppleGoogleAmazon	Medium	Command & Composite Patterns, State Synchronization, Observer Registry, Bounded History Logs

Messaging

0/2 solved

Status	Star	Problem	Difficulty	Key Focus	Notes
		Email Client Asked by:GoogleMicrosoftYahoo	Medium	Search, Folder Hierarchy
		Email Search Engine Asked by:GoogleMicrosoftYahoo	Hard	Inverted Index, Threading

Resilience

0/1 solved

Status	Star	Problem	Difficulty	Key Focus	Notes
		Circuit Breaker Asked by:NetflixAWSGoogle+1 more	Medium	State Transitions (Open/Closed)

0/1 solved

Status	Star	Problem	Difficulty	Key Focus	Notes
		Ad-Serving Engine Asked by:GoogleTradeDeskMeta	Hard	Bid Selection, Auction Logic

Security

0/1 solved

Status	Star	Problem	Difficulty	Key Focus	Notes
		Auth Service (OAuth / SSO) Asked by:OktaMicrosoftAuth0+1 more	Hard	Token Rotation, RBAC/ABAC

Media

0/1 solved

Status	Star	Problem	Difficulty	Key Focus	Notes
		Podcast Player Asked by:SpotifyAppleGoogle	Medium	State (Play/Pause), Playlists

Management

0/1 solved

Status	Star	Problem	Difficulty	Key Focus	Notes
		Health Tracker Asked by:AppleFitbitGoogle	Easy	Time-series Data Aggregation

DevOps

0/1 solved

Status	Star	Problem	Difficulty	Key Focus	Notes
		On-Call Pager / Escalation System Asked by:PagerDutyAtlassianGoogle	Medium	Escalation State Machine

ML

0/1 solved

Status	Star	Problem	Difficulty	Key Focus	Notes
		Feature Store (ML) Asked by:UberFeastTecton+2 more	Hard	Point-in-time Correctness

Web Services

0/1 solved

Status	Star	Problem	Difficulty	Key Focus	Notes
		Pastebin (LLD) Asked by:GoogleDropboxAmazon	Easy	TTL, Base62 Encoding