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Master LLD with Adaptive AI.
Master LLD across 69 patterns - LLD - guided by Leyaa's adaptive intelligence.
10Topics
69Patterns
15hEst. duration
LLD Course
10 topics
Design Patterns - Applied
17 patterns
Booking and Reservation Systems
5 patterns
Game Design
5 patterns
Financial and E-Commerce OOP
5 patterns
Advanced LLD Challenges
6 patterns
Infrastructure and Utility Systems
7 patterns
Library and Catalog Systems
5 patterns
Social and Professional Platforms
5 patterns
Systems with State Machines
5 patterns
OOP Foundations for Interviews
9 patterns
Curriculum
Everything You'll Learn
Explore every pattern in the course.
LLD
10 topics · 69 patterns01
Design Patterns - Applied
17 patterns
Abstract Factory Pattern - Creating Families of Related ObjectsAdapter Pattern - Making Incompatible Interfaces Work TogetherBuilder Pattern - Constructing Complex Objects Step by StepChain of Responsibility - Passing Requests Through a Chain of HandlersCommand Pattern - Encapsulating Operations for Undo, Redo, QueueDecorator Pattern - Adding Behavior to Objects Without InheritanceFacade Pattern - Simplifying Complex Subsystems for ClientsFactory Pattern - Object Creation Without Coupling the CallerIterator Pattern - Traversal Without Exposing Internal StructureObserver Pattern - Event-Driven Design and Decoupling Publisher from SubscriberPrototype Pattern - Cloning Objects When Construction Is ExpensiveProxy Pattern - Access Control, Lazy Loading, Caching ProxySingleton Pattern - Thread-Safe Implementation and When to Avoid ItState Pattern - Modeling Finite State Machines in ATM, Elevator, Vending MachineStrategy Pattern - Pluggable Algorithms and Runtime Behavior SwapTemplate Method Pattern - Defining Algorithm Skeleton, Subclasses Fill In StepsWhy Design Patterns Exist and When Not to Use Them
02
Booking and Reservation Systems
5 patterns
03
Game Design
5 patterns
Design a Card Game Framework - Deck, Card, Hand, Rules Engine, MultiplayerDesign a Chess Game - Board, Pieces, Move Validation, Check Detection, TurnSnake and Ladder GameDesign an Online Blackjack Game - Deck, Hand, Dealer, Betting, Win ConditionDesign an Online Tic-Tac-Toe Game - Board, Player, Win Detection, Replay
04
Financial and E-Commerce OOP
5 patterns
05
Advanced LLD Challenges
6 patterns
Jigsaw Puzzle SystemDesign a Plugin Architecture - Plugin Interface, Registry, Loader, DependencyRestaurant Management SystemDesign a Workflow Engine - Step, Transition, Condition, Executor, State StoreESPNcricinfo System - Match, Innings, Ball, Scorecard, CommentaryDesign an In-Memory SQL Database - Table, Row, Column, Query Parser, Indexing
06
Infrastructure and Utility Systems
7 patterns
Job SchedulerDesign a Logging Framework - Log Levels, Appenders, Formatters, Log RotationNotification System OOP - Factory Pattern, Channel Abstraction, TemplateDesign a Rate Limiter Class - Token Bucket OOP Implementation with Thread SafetyDesign a Ride Booking Class Hierarchy - Driver, Rider, Trip, Vehicle, Fare CalculationIn-Memory File SystemDesign an LRU Cache - O(1) Get and Put Using HashMap and Doubly Linked List
07
Library and Catalog Systems
5 patterns
08
Social and Professional Platforms
5 patterns
Design a Messaging System OOP - User, Conversation, Message, Delivery StatusDesign a Social Media Profile System - User, Follow, Post, Like, Feed OOPDesign Facebook in OOP - User, Friend, Post, Group, Event, Privacy ModelDesign LinkedIn in OOP - Profile, Connection, Feed, Job, RecommendationDesign Stack Overflow in OOP - Question, Answer, Vote, Tag, Reputation, Bounty
09
Systems with State Machines
5 patterns
Traffic Light System - State Machine, Sensor Input, Emergency OverrideDesign a Vending Machine - States, Product Selection, Payment, Change, RefillDesign an ATM System - States, Transitions, Card, PIN, Transaction, SecurityElevator System - Scheduling Algorithm, Multiple Lifts, Floor QueueOrder Management System
10
OOP Foundations for Interviews
9 patterns
DRY, KISS, YAGNI - Principles That Prevent Over-Engineering in InterviewsHow to Approach Any LLD Problem in 45 Minutes - Step-by-Step FrameworkInterface vs Abstract Class - When Each Is the Right ChoiceRequirements Gathering for LLD - What Questions to Ask the InterviewerSOLID Principles - Single Responsibility to Dependency Inversion with Real CodeThe 4 OOP Pillars with Interview Examples - Encapsulation, Abstraction, Inheritance, PolymorphismUML Class Diagrams - Reading and Drawing Relationships, Multiplicity, NotationWhen to Use Inheritance vs Composition - The Rule Every Senior Engineer KnowsWhy LLD Exists and What HLD Cannot Tell You
Why LeyaaNot just a course. A learning intelligence.
Leyaa doesn't just deliver content - it understands where you are, what you need, and how to get you there fastest.
Adaptive Diagnostics
Leyaa identifies which of the 69 patterns you've mastered and which need work - before you waste time on what you already know.
Pattern-Level Precision
Every pattern gets a verdict - Learn, Practice, or Skip - so your study time goes exactly where it counts.
Intelligent Pacing
Leyaa reads your velocity across the whole course and adapts your focus list dynamically, keeping you in the optimal learning zone.
Before & After Visibility
Every assessment creates a snapshot. Retake anytime to see exactly how much you've grown - pattern by pattern.
Learner Autonomy
Leyaa recommends, never restricts. Override any suggestion and explore at your own pace - the system tracks everything regardless.
Clear Learning Path
A structured journey through 10 topics, where each one sets you up perfectly for the next.
LLD
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69 Patterns
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