What is Design Patterns?
Reusable solutions to commonly occurring problems in software design. They provide proven templates for structuring code to be more maintainable, flexible, and understandable.
In plain English
Design patterns are like architectural blueprints for common building types. Just as architects don't redesign hospitals or schools from scratch every time, software engineers use established patterns to solve recurring problems. The pattern isn't the code itself — it's the template for organizing code.
How it works
Design patterns fall into three main categories: Creational (how objects are created — Factory, Singleton, Builder), Structural (how objects are composed — Adapter, Decorator, Facade), and Behavioral (how objects communicate — Observer, Strategy, Command). In modern JavaScript/TypeScript, patterns like the Module pattern, Observer pattern (event emitters), and Strategy pattern (swappable algorithms) are especially common.
Why it matters for AI-built apps
AI coding tools produce code that works but often lacks structural patterns. This leads to code that's hard to modify, test, and extend. Understanding common patterns helps you recognize when AI-generated code should be refactored — for example, replacing a chain of if-else statements with the Strategy pattern, or using the Observer pattern instead of tightly coupled event handling.
Common issues
Over-engineering with unnecessary patterns (a Singleton for something used once), using patterns incorrectly (creating a God Object and calling it a Facade), not recognizing when a pattern would solve a recurring problem, and AI tools generating procedural code where patterns would improve structure.
Best practices
Learn the most common patterns for your stack (React: HOC, Render Props, Custom Hooks, Compound Components; Node: Middleware, Repository, Event Emitter). Apply patterns to solve actual problems, not to demonstrate cleverness. Refactor toward patterns when you notice recurring structural issues. Keep it simple — the right pattern should make code easier to understand, not harder.
Frequently asked questions
Do I need to learn design patterns for my AI-built app?
You don't need to memorize all 23 Gang of Four patterns, but understanding a few key ones helps you evaluate and improve AI-generated code. Focus on patterns common in your stack: for React/Next.js, learn Custom Hooks, Compound Components, and the Container/Presentational pattern. For backends, learn Repository, Middleware, and Strategy patterns.
How do I know when AI-generated code needs a design pattern?
Watch for code smells: large functions doing many things, switch statements that grow with every new feature, tightly coupled components, duplicated logic across files, and objects that need to notify other objects of changes. These are signs that a pattern like Strategy, Observer, or Factory would improve the code's structure and maintainability.
Check your app
Get a professional review of your app at a fixed price.
Security Scan
Black-box review of your public-facing app. No code access needed.
- OWASP Top 10 checks
- SSL/TLS analysis
- Security headers
- Expert review within 24h
Code Audit
In-depth review of your source code for security, quality, and best practices.
- Security vulnerabilities
- Code quality review
- Dependency audit
- AI pattern analysis
Complete Bundle
Both scans in one package with cross-referenced findings.
- Everything in both products
- Cross-referenced findings
- Unified action plan
100% credited toward any paid service. Start with an audit, then let us fix what we find.
Worried about design patterns in your app?
Get a professional code audit ($19) or book a free call to discuss your concerns.