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Low-Level Design

Foundations and Interview Framework

1.What Is Low-Level Design?
2.The Low-Level Design Interview Framework
3.Modeling Domains in Java: From Nouns to Types
4.Class Diagrams and Relationships in Java

Design Principles

5.SOLID Principles in Java
6.Encapsulation and Invariants in Java
7.State Machines with Sealed Types
8.Errors in Domain Design
9.Object Graphs and References
10.Testability and Dependency Injection

Concurrent Components

11.Thread-Safe Components in Java
12.Event Bus and Observers in Java
13.Blocking Queue and Producer-Consumer in Java

Data-Structure-Centric Problems

14.Design an LRU Cache (Low-Level Design)
15.Design a Key-Value Store with TTL in Java (Low-Level Design)
16.Low-Level Design of a Rate Limiter in Java
17.Design a Logger Framework in Java (Low-Level Design)
18.Design a Task Scheduler (Low-Level Design)
19.Design a Text Editor with Undo and Redo (Low-Level Design)
20.Design an In-Memory File System in Java (Low-Level Design)

Domain Modeling Problems

21.Design a Parking Lot
22.Design an Elevator System
23.Design a Vending Machine in Java
24.Design an ATM in Java
25.Design a Library Management System
26.Design Tic-Tac-Toe (NxN) in Java
27.Design Splitwise (Expense Sharing) in Java
28.Design a Movie Ticket Booking System in Java
29.Design a Notification Service in Java

Cheat Sheets and Study Plan

30.LLD Interview Checklist
31.LLD Study Plan: A 4-Week Path Through the Course

Low-Level Design

Foundations and Interview Framework

1.What Is Low-Level Design?
2.The Low-Level Design Interview Framework
3.Modeling Domains in Java: From Nouns to Types
4.Class Diagrams and Relationships in Java

Design Principles

5.SOLID Principles in Java
6.Encapsulation and Invariants in Java
7.State Machines with Sealed Types
8.Errors in Domain Design
9.Object Graphs and References
10.Testability and Dependency Injection

Concurrent Components

11.Thread-Safe Components in Java
12.Event Bus and Observers in Java
13.Blocking Queue and Producer-Consumer in Java

Data-Structure-Centric Problems

14.Design an LRU Cache (Low-Level Design)
15.Design a Key-Value Store with TTL in Java (Low-Level Design)
16.Low-Level Design of a Rate Limiter in Java
17.Design a Logger Framework in Java (Low-Level Design)
18.Design a Task Scheduler (Low-Level Design)
19.Design a Text Editor with Undo and Redo (Low-Level Design)
20.Design an In-Memory File System in Java (Low-Level Design)

Domain Modeling Problems

21.Design a Parking Lot
22.Design an Elevator System
23.Design a Vending Machine in Java
24.Design an ATM in Java
25.Design a Library Management System
26.Design Tic-Tac-Toe (NxN) in Java
27.Design Splitwise (Expense Sharing) in Java
28.Design a Movie Ticket Booking System in Java
29.Design a Notification Service in Java

Cheat Sheets and Study Plan

30.LLD Interview Checklist
31.LLD Study Plan: A 4-Week Path Through the Course

Home/Low-Level Design/Design Principles

Design Principles

SOLID, encapsulation, state machines, error modeling, object graphs and references, and designing for tests.

6 lessons

5.SOLID Principles in Java
6.Encapsulation and Invariants in Java
7.State Machines with Sealed Types
8.Errors in Domain Design
9.Object Graphs and References
10.Testability and Dependency Injection

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