Low-Level Design for MAANG Interviews

A book-shaped table of contents for LLD interview prep: OOP fundamentals through SOLID, design principles, UML, design patterns, dependency management, reliability, concurrency, domain modeling, API design, testing, refactoring, classic interview problems, advanced architecture, and performance — cross-linking Object-Oriented Programming and Patterns instead of duplicating them.

1 — Thread Safety

Defines what it means for a class or method to be thread-safe and the correctness guarantees a design must uphold under concurrent access.

3 — Locks

Examines lock types — mutexes, read-write locks, reentrant locks — and the tradeoffs each makes between safety and throughput.

4 — Concurrent Collections

Surveys concurrent collection types designed for safe multi-threaded access without requiring external locking by the caller.

5 — Producer Consumer

Walks through the producer-consumer pattern for decoupling work generation from work processing via a shared bounded queue.