Many pattern-based methods for development are the result of experiences with very specific technologies. The famous "Gang of Four" Design Patterns, for example, were largely a response to the challenges and constraints of languages like C++ and early Java. While the ideas behind them are grounded in good intentions, they can quickly introduce limitations and dogma that put you at a disadvantage when dealing with the rapid pace of change today.
These patterns have become more academic than realistically applicable to engineering many modern solutions. The risk is that we teach engineers to memorize the solutions themselves, rather than to understand the fundamental problems that led to their creation.
The Danger of Dogma
When an engineer treats a pattern as a rule to be followed, they stop thinking from first principles. They might force a complex pattern into a situation where a simple function would suffice, simply because it "fits" the definition they learned. This is particularly dangerous in modern languages, which often have built-in features (like first-class functions, decorators, or advanced type systems) that elegantly solve the very problems the old patterns were designed to work around.
Applying a 20-year-old solution to a modern problem can lead to verbose, over-engineered code that is harder to read and maintain than a simpler, more idiomatic approach.
The Real Lesson: From Patterns to Principles
The value of studying classic design patterns is not to create a mental catalog of solutions to copy and paste. The best approach is to view them as a history book, not a rule book. We should learn the concepts and reasons why they were established in order to recognize those types of issues and their potential for occurring in new circumstances.
Instead of memorizing the Singleton pattern, understand the challenges of managing global state. Instead of memorizing the Visitor pattern, understand the principle of separating an algorithm from the object structure it operates on.
This approach provides two key benefits:
- Awareness: It equips you with the awareness to identify fundamental challenges (like state management, decoupling, or abstraction) when they appear in new frameworks and technologies.
- Flexibility: It frees you to use the best tools available in your current environment to solve the problem, rather than forcing an outdated solution.
Patterns give us a good history lesson to learn the fundamentals. This, in turn, gives us the awareness to forge new, better solutions and avoid repeating the costly mistakes of the past.