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Low-Level Design

OOP, SOLID and design patterns, then full machine-coding case studies with working Java code: parking lot, elevator, BookMyShow, Splitwise and more.

1Foundations

LLD Basics~23 min read OOP for LLD~19 min read SOLID~18 min read UML Diagrams~19 min read

2Design patterns

Creational Patterns~19 min read Structural Patterns~18 min read Behavioural Patterns~21 min read

3Case studies

Parking Lot~25 min read Elevator System~23 min read Movie Ticket Booking~21 min read Splitwise~18 min read LRU Cache and Rate Limiter~22 min read Vending Machine and ATM~20 min read

4Interview practice

LLD Interview Practice~23 min read

Your preparation pack

Free · Self-paced

14 lessons in 4 modules

Follow a repeatable framework in machine-coding rounds
Apply SOLID and explain each principle with code
Draw class diagrams with the right relationships
Pick the right creational, structural or behavioural pattern
Write thread-safe, extensible designs with working code

Exercises support self-assessment. This free pack does not award a certificate or guarantee placement.