03 — SOLID Revisited — Principal-Level Framing

1 — SOLID Principles

Breaks down Single Responsibility, Open/Closed, Liskov Substitution, Interface Segregation, and Dependency Inversion — the five pillars of class-level design discipline.

Object-Oriented Programming for MAANG Interviews

A book-shaped table of contents for OOP: paradigm foundations, the four pillars, object relationships, SOLID/GRASP design principles, memory and runtime internals, GoF design patterns, language-specific OOP, and OOP at system scale — cross-linking existing pattern, concurrency, and low-level-design notes instead of duplicating them.

Patterns

A book-shaped table of contents for reusable engineering patterns spanning object-oriented design, enterprise architecture, distributed systems, messaging, APIs, cloud infrastructure, observability, security, concurrency, AI/agentic systems, and organizational design — grounded in production experience at scale.

02 — Pattern Selection & Trade-offs

How to choose between competing patterns under real forces: naming the context, weighing trade-offs and consequences, composing multiple patterns together, and recognizing when a pattern has outlived its fit.

01 — What Is a Pattern?

The history and vocabulary of pattern thinking — Christopher Alexander's pattern language, the Gang of Four's catalog, anti-patterns, and how a pattern differs from a one-off design decision.

Patterns

A book-shaped table of contents for reusable engineering patterns spanning object-oriented design, enterprise architecture, distributed systems, messaging, APIs, cloud infrastructure, observability, security, concurrency, AI/agentic systems, and organizational design — grounded in production experience at scale.

03 — Transaction Patterns

Unit of Work, Identity Map, Lazy Loading, and Optimistic vs. Pessimistic Locking — the patterns that keep an object graph and its persisted state from drifting apart.