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Master LLD with Adaptive AI.

Master LLD across 18 topics - Foundations, Intermediate, and Advanced - guided by Leyaa's adaptive intelligence.

3Parts
18Topics
134Patterns
35hEst. duration
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LLD
LLD Course
3 - part learning journey
Beginner
Foundations
6 topics · 48 patterns
Beginner
Intermediate
Intermediate
6 topics · 44 patterns
Intermediate
Advanced
Advanced
6 topics · 42 patterns
Advanced
Begin Part 1: Foundations
✦ Course Structure

Your LLD Journey in 3 Parts

Each part builds on the last - a deliberate progression from beginner to advanced.

Beginner
Beginner
Part 1: Foundations
Covers LLD Basics and Object-Oriented Thinking, SOLID Principles, UML Diagrams and 3 more topics.
6Topics
48Patterns
View topics
Intermediate
Intermediate
Part 2: Intermediate
Covers Behavioral Design Patterns — Part 1, Behavioral Design Patterns — Part 2 and 4 more topics.
6Topics
44Patterns
View topics
Advanced
Advanced
Part 3: Advanced
Covers Design — Chess Game, Design — Online Shopping Cart, Design — Food Delivery System and 3 more topics.
6Topics
42Patterns
View topics
Curriculum

Everything You'll Learn

Explore every topic and pattern in the course.

LLD

3 parts · 18 topics · 134 patterns
Beginner
Part 1: Foundations6 topics · 48 patterns
Beginner
01
LLD Basics and Object-Oriented Thinking
7 patterns
Why low level design produces clean code
What LLD covers vs HLD
Object-oriented design principles
Identifying classes from requirements
Class responsibilities and behavior
UML class diagrams basics
LLD interview expectations
02
SOLID Principles
8 patterns
Why SOLID principles guide maintainable design
Single Responsibility Principle
Open/Closed Principle
Liskov Substitution Principle
Interface Segregation Principle
Dependency Inversion Principle
SOLID violations and fixes
Applying SOLID to real code
03
UML Diagrams
8 patterns
Why UML communicates design visually
Class diagrams
Relationships (association, aggregation, composition)
Inheritance and interface notation
Sequence diagrams
Use case diagrams
Activity diagrams
State diagrams
04
Design Principles Beyond SOLID
9 patterns
Why additional principles improve quality
DRY (Don't Repeat Yourself)
KISS (Keep It Simple)
YAGNI (You Aren't Gonna Need It)
Composition over inheritance
Program to interface not implementation
Law of Demeter
Separation of concerns
Encapsulation and information hiding
05
Creational Design Patterns
7 patterns
Why creational patterns manage object creation
Singleton pattern
Factory Method pattern
Abstract Factory pattern
Builder pattern
Prototype pattern
When to use which creational pattern
06
Structural Design Patterns
9 patterns
Why structural patterns organize class relationships
Adapter pattern
Bridge pattern
Composite pattern
Decorator pattern
Facade pattern
Flyweight pattern
Proxy pattern
When to use which structural pattern
Intermediate
Part 2: Intermediate6 topics · 44 patterns
Intermediate
01
Behavioral Design Patterns — Part 1
8 patterns
Why behavioral patterns define object interaction
Strategy pattern
Observer pattern
Command pattern
Template Method pattern
Iterator pattern
State pattern
Chain of Responsibility pattern
02
Behavioral Design Patterns — Part 2
7 patterns
Why more behavioral patterns solve communication
Mediator pattern
Memento pattern
Visitor pattern
Interpreter pattern
Null Object pattern
When to use which behavioral pattern
03
Design — Parking Lot System
8 patterns
Why parking lot is a classic LLD problem
Requirements analysis
Class identification (ParkingLot, Floor, Spot, Vehicle)
Enum usage (VehicleType, SpotType)
Parking strategy pattern
Payment handling
Entry and exit flow
Concurrency considerations
04
Design — Library Management System
7 patterns
Why library management tests CRUD design
Requirements and use cases
Class design (Book, Member, Librarian, Loan)
Search functionality design
Reservation and hold system
Fine calculation
Notification system
05
Design — Elevator System
6 patterns
Why elevator design tests state machines
Elevator, Floor, Request classes
Scheduling algorithm (SCAN, LOOK)
State management (idle, moving up, moving down)
Multiple elevator coordination
Emergency handling
06
Design — Tic-Tac-Toe Game
8 patterns
Why game design tests model-view separation
Requirements and game rules
Board, Player, Game classes
Move validation
Win condition checking
Player turn management
Extensibility (NxN board, multiple players)
Command pattern for undo
Advanced
Part 3: Advanced6 topics · 42 patterns
Advanced
01
Design — Chess Game
7 patterns
Why chess tests polymorphism and strategy
Board and piece hierarchy
Piece movement rules (polymorphism)
Move validation and check detection
Special moves (castling, en passant)
Game state management
Observer pattern for UI updates
02
Design — Online Shopping Cart
7 patterns
Why e-commerce tests real-world complexity
Product, Cart, Order classes
Pricing strategy (discounts, coupons)
Inventory management
Payment strategy pattern
Order state machine
Notification on state change
03
Design — Food Delivery System
6 patterns
Why delivery systems test service coordination
Restaurant, Menu, Order classes
Delivery agent assignment
Order tracking state machine
Rating and review system
Notification to all parties
04
Design — Hotel Booking System
7 patterns
Why booking tests availability and concurrency
Hotel, Room, Booking classes
Room type hierarchy
Availability checking
Booking conflict resolution
Cancellation and refund policy
Search and filter design
05
Design — Splitwise (Expense Sharing)
6 patterns
Why Splitwise tests financial logic
User, Group, Expense classes
Split strategies (equal, exact, percentage)
Balance calculation algorithm
Simplify debts algorithm
Transaction history
06
Advanced LLD Concepts
9 patterns
Why advanced concepts handle production systems
Thread safety in design
Immutability for safety
Event-driven design
Dependency injection framework
Clean Architecture layers
Domain-Driven Design basics
Anti-patterns to avoid
Code review checklist for LLD
Why Leyaa

Not 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
Adaptive Diagnostics
Leyaa identifies which of the 134 patterns you've mastered and which need work - before you waste time on what you already know.
Pattern-Level Precision
Pattern-Level Precision
Every pattern gets a verdict - Learn, Practice, or Skip - so your study time goes exactly where it counts.
Intelligent Pacing
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
Before & After Visibility
Every assessment creates a snapshot. Retake anytime to see exactly how much you've grown - topic by topic, pattern by pattern.
Learner Autonomy
Learner Autonomy
Leyaa recommends, never restricts. Override any suggestion and explore at your own pace - the system tracks everything regardless.
Clear Learning Path
Clear Learning Path
Foundations → Intermediate → Advanced - a structured journey where each part sets you up perfectly for the next.
LLD

Ready to master LLD?
Start your journey today

Start your diagnostic now. Build mastery across all 18 topics in under 15 minutes.

18 Topics
134 Patterns
Personalized roadmap
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