Design Patterns

💬 In plain words: Classic software design patterns translate beautifully to Salesforce Apex, but they look a bit different. The Singleton pattern ensures one shared instance per transaction (great for caching). The Strategy pattern lets you swap out business rules cleanly. The Factory pattern creates the right class dynamically based on configuration. Mastering these patterns—and knowing which ones the Salesforce platform handles natively—is the key to writing scalable, enterprise-grade code. 📌 Example: Config-Driven Validation Imagine your company handles global orders: US orders require a Tax ID, while EU orders require a VAT check. Instead of a massive if/else chain, use the Strategy pattern . Create one IOrderValidator interface and separate classes for each country. Then, use a Factory to read a Custom Metadata Type and load the correct class dynamically. When you expand to a new country, you just write a new class and add one config ro...