Software Design & Architecture
Design principles, design patterns and architectural thinking for production software.
Essential Software Design Principles Every Developer Should Know
A practical overview of the design principles that separate junior and senior engineers — DRY, KISS, YAGNI, SOLID, separation of concerns and more.
DRY, KISS, and YAGNI Explained
Three short acronyms that prevent most over-engineering — what DRY, KISS and YAGNI mean and how to apply them without going too far.
Composition Over Inheritance in Java
Why Java developers should prefer composition over inheritance — with side-by-side refactoring examples that show why composition scales better.
Coupling vs Cohesion Explained
What coupling and cohesion mean, why every senior engineer cares about them, and how to recognize the smells in your own code.
Common Object-Oriented Design Mistakes
The OO design mistakes that show up in code reviews most often — and the simple refactors that fix them.
Singleton Pattern in Java
Implement the Singleton pattern correctly in Java — thread safety, enum singletons, and why Spring beans are a better default.
Factory Pattern Explained with Real Examples
How and when to use the Factory pattern in Java — encapsulate object creation, decouple clients from concrete classes, and keep code testable.
Builder Pattern for Clean Object Creation
Use the Builder pattern to construct complex objects step by step — readable, immutable, and free from telescoping constructors.
Strategy Pattern for Flexible Business Logic
The Strategy pattern in Java — swap algorithms at runtime, eliminate switch statements, and keep code open for extension.
Observer Pattern in Event-Driven Systems
Build decoupled event-driven code with the Observer pattern — Java examples plus Spring's ApplicationEventPublisher in practice.
Adapter Pattern in Spring Boot
Use the Adapter pattern to bridge incompatible interfaces — practical Spring Boot examples integrating third-party libraries and legacy code.
Decorator Pattern Explained Simply
Add behavior to objects at runtime without subclassing — the Decorator pattern in Java with caching, logging and retry examples.
Modular Monolith Architecture in Spring Boot — The Right Way to Scale a Monolith
Why modern teams are returning to modular monoliths — module boundaries, package-by-feature, internal events and a clean migration path to microservices in Spring Boot.
Hexagonal Architecture with Spring Boot — Build Clean, Maintainable Applications
A practical guide to Ports and Adapters (Hexagonal Architecture) in Spring Boot — isolate your domain, make your code testable, and keep infrastructure swappable.
Domain-Driven Design (DDD) with Spring Boot — Practical Guide for Real Systems
A no-nonsense guide to Domain-Driven Design with Spring Boot — bounded contexts, aggregates, value objects, domain events and how to apply DDD without ceremony.
CQRS Pattern in Spring Boot — Separating Reads and Writes for Scale
A complete production guide to the CQRS pattern in Spring Boot — write models, query models, event projections, Kafka integration, consistency trade-offs and real-world scaling patterns.
The Outbox Pattern — Reliable Event Publishing in Microservices
Solve the dual-write problem with the transactional Outbox pattern. Production guide using Spring Boot, JPA, PostgreSQL, Kafka and Debezium with idempotent consumers and operational best practices.