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 — Appendix A: UML Cheat Sheet

Quick-reference summary of UML notation — class, sequence, and relationship symbols — for fast lookup while sketching an LLD design.

2 — Appendix B: SOLID & GRASP Cheat Sheet

Quick-reference summary of the five SOLID principles and the GRASP responsibility-assignment patterns, condensed for interview recall.

3 — Appendix C: Design Pattern Decision Matrix

Cross-references common design problems against candidate GoF patterns so the right pattern can be picked quickly instead of pattern-matched from memory.

5 — Appendix E: Java Implementation Guidelines

Language-specific guidance for translating an LLD whiteboard design into idiomatic Java — interfaces, access modifiers, and collection choices.