I've been a software eng professionally for 25 years. Have been coding more like 30 - 35. There is a fundamental principal here that I agree with and it surrounds a code smell that Martin Fowler termed "Speculative Generality" in his book "Refactoring."

Speculative Generality is when you don't know what will have to change in the future and so you abstract literally everything and make as many things "generic" as you possibly can in the chance that one of those generic abstractions may prove useful. The result is a confusing mess of unnecessary abstractions that adds complexity.

However, yet again I find myself staring at a reactionary post. If developers get themselves into trouble through speculative generality, then the answer is clearly "Primitive Obsession" (another code smell identified in "Refactoring") right?

Primitive Obsession is the polar opposite of abstraction. It dispenses with the introduction of high-level APIs that make working with code intuitive, and instead insists on working with native primitive types directly. Primitive Obsession often comes from a well meaning initiative to not "abstract prematurely." Why create a "Money" class when you can just store your currency figure in an integer? Why create a "PersonName" class when you can just pass strings around? If you're working in a language that supports classes and functions, why create a class to group common logical operations around a single data structure when you can instead introduce functions even if they take more parameters and could potentially lead to other problems such as "Shotgun Surgery."

This is not to say that the author is wrong or that one should embrace "premature abstraction." Only that I see a lot of reactionary thinking in software engineering. Most paradigms that we have today were developed in order to solve a very real problem around complexity at the time. Without understanding what that complexity was, historically, you are doomed to repeat the mistakes that the thinkers at the time were trying to address.

And of course, those iterations introduced new problems. Premature Abstraction IS a "foot gun." What software engineers need to remember is that the point of Design Patterns, the point of Abstractions, the point of High-Level languages and API design is to SIMPLIFY.

One term we hear a lot, that I have been on the war path against for the past decade or two is "over engineering." As engineers, part of our jobs is to find the simplest solution to a given problem. If, in your inappropriate use of a given design pattern or abstraction, you end up making something unnecessarily complicated, you did not "over engineer" it. You engaged in BAD engineering.

When it comes to abstractions, like anything else, the key to gain the experience needed to understand a) why abstractions are useful b) when abstractions can introduce complexity and then apply that to a prediction of what will likely benefit from abstraction because it is something that will be very difficult to change later.

All software changes. That's the nature of software and why software exists in the first place. Change is the strength of software but also a source of complexity. The challenge of writing code comes from change management. Being able to identify which areas of your code are going to be very difficult to change later, and to find strategies for facilitating that change.

Premature Abstraction throws abstractions at everything, even things that are unlikely to change, without the recognition that doing so makes the code more complex not less. Primitive Obsession says "we can always abstract this later if we need to" when in some situations, that will prove impossible(ex: integrating with and coupling to a 3rd party vendor; a form of "vendor lock-in" through code that is often seen).

/stream-of-consciousness-thoughts-on-article