Summary

Pattern Comparison

Pattern	When to Apply	Strengths	Caveats	Common Use Cases
Template Method	When the overall process is fixed but steps vary	Defines a consistent structure, highlights differences	Inheritance-based; less flexible	Save operations, batch processing
Strategy	When switching core logic	Highly flexible, easy to test	May lead to many small classes	Notifications, billing
Decorator	When adding additional behavior incrementally	Composable and reusable	Too many layers can reduce readability	Logging, validation
Visitor	When multiple operations need to be applied	Adds new behavior without changing data structure	Can get complex with many operations	Export formats, AST processing
Prototype	When duplicating similar objects	Easy reuse and modification of copies	Requires careful clone() implementation	Configs, notification templates, UI parts

Choosing the Right Pattern

• Repeated logic patterns? → Start with Template Method
• Shared workflow with small differences → Template Method
• Focused on switching logic → Strategy
• Want to layer behavior without altering core logic → Decorator
• Want to separate data structure from behavior → Visitor
• Duplicating similar objects with minor changes → Prototype

Team Discussion Snippets

• “This looks nearly identical—let’s use Template Method and isolate the differences.”
• “If we just want to swap out the logic, Strategy will give us more flexibility.”
• “Need to add logging? Wrapping it with a Decorator will keep it modular.”
• “We’re outputting to different formats—Visitor can cleanly separate that logic.”
• “Using variations of the same object? A Prototype with cloning will help streamline this.”