Layered architecture gets a lot of flack.
Even though it’s still the most prevalent architecture, we view it as an anti-pattern. It’s old, not scaleable, and anti-SOLID. It encourages (shudder) monoliths!
Yes, I know. Hexagonal architecture is the way to go. Or maybe I’m feeling a taste for onions. But only if it’s clean!
The point is that even though it may not be an object-oriented nirvana, layered architecture is still a useful pattern. And if done right, it paves the way towards more advanced designs and architecture.
So let’s talk about layers.
Continue reading Layered Architecture: Still a Solid Approach
In the spirit of the Agile Manifesto, we’ve reduced our dependence on software documentation.
In some ways, this has improved our lives. And in other ways, it’s been taken too far and had the opposite effect.
In this post, we’ll take a look at the balance of these concerns in relation to a software architecture document. What is this, and when do you need it?
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Understanding the Need for Balance
The Agile Manifesto values “working software over comprehensive documentation,” which isn’t to say that documentation isn’t necessary.
All too often, the baby is thrown out with the bathwater, and teams produce little to no documentation at all—including the software architecture document.
So which bits of documentation should we throw out and which should we still deliver?
Indeed, we should prioritize those deliverables like any other user story. Some organizations will place a higher value on certain documents than others. Nearly all should put more priority on creating a software architecture document.
Continue reading Software Architecture Document? Do You Need One?
Design patterns seem to be a controversial topic. On one hand, many developers seem to love them and treat the famous book by the Gang of Four like sacred scripture. On the other hand, many developers loath the very idea of design patterns. It’s not too hard to find posts around the web with titles such as “Design Patterns are Bad Design,” “Following Design Patterns Is A Bad Idea,” and of course, the inevitable “Design Patterns Considered Harmful.”
What can we take from that? Well, as it is with pretty much everything in our industry, it’s really hard to reach some form of consensus on design patterns. My take is this: design patterns are tools. Some are more useful, others less useful. Some may be outright harmful. And others may not make sense for your scenario, but maybe for Joe who sits three desks from you, they’re a gift from heaven.
But that’s not what this post is really about (i.e. deciding whether design patterns are “good” or “bad”). As we’ve seen, such discussion is simplistic and misses the point.
What we’re going to do instead is cover three design patterns that haven’t aged quite well. These design patterns are ones that you no longer go around implementing. And if you do, you probably shouldn’t.
Let’s get started.
Continue reading 3 Design Patterns That Have Aged Poorly
When I was attending night school to become a programmer, I learned several design patterns: singleton, repository, factory, builder, decorator, etc. Design patterns give us a proven solution to existing and recurring problems. What I didn’t learn was that a similar mechanism exists on a higher level in the form of the software architecture pattern.
These are patterns for the overall layout of your application or applications. They all have advantages and disadvantages. And they all address specific issues.
In this post, we’ll take a look at 5 such patterns in detail. For each software architecture pattern, this will include a description, its advantages, its disadvantages, and the situation for which it is ideal. The patterns are as follows.
- The Layered Architectural Pattern
- The Microkernel Architectural Pattern
- The CQRS Architectural Pattern
- The Event Sourcing Architectural Pattern
- The Microservices Architectural Pattern
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Continue reading Software Architecture: The 5 Patterns You Need to Know
After a somewhat long delay, it’s time to finally continue our series on clean architecture. This is the second post in the inner series in which we show you a quick implementation of said architecture and the third post in the overall series. In case you haven’t read the previous posts, please do so by using the links in the series layout below:
Without further ado, let’s continue our implementation.
Continue reading Continuing Our Clean Architecture Example in C#
Ah, the old “versus” Google search. Invariably, you’re in the research stage of some decision when you type this word into a search engine. Probably not something like Coke vs Pepsi. Maybe “C# vs Java for enterprise projects” or “angular vs react.” Or if you landed here, perhaps you’re looking at “log4net vs NLog.”
With a search like this, you expect a certain standard script. The writer should describe each one anecdotally, perhaps with a history. Then comes the matrix with a list of features and checks and exes for each one, followed by a sober list of strengths and weaknesses. Then, with a flourish, I should finish with a soggy conclusion that it really depends on your needs, but I maybe kinda sorta like one better.
I’m not going to do any of that. Continue reading Log4net vs NLog: A Comparison of How They Affect Codebases
Programming languages come in all shapes and sizes: interpreted vs. compiled, weak vs. strong typing, low-level vs. high-level, terse vs. expressive… There are many buckets you can put a programming language into, even though not all are equally meaningful.
One very common way people classify languages is to organize them into paradigms. You can think of a paradigm as a group of languages that share similar characteristics. There are many paradigms currently in use: procedural, functional, and object-oriented. Many of these terms are often misused or confused; there’s also some degree of overlap between different paradigms, which definitely doesn’t make things easier.
Add all of that together and what you get is a landscape that’s not too easy for a beginner to grasp. In today’s post, we’ll try and fix this situation by giving you a clear picture of the imperative programming paradigm.
Continue reading Imperative Programming in Depth
Software development is a very young field, particularly when you compare it to, say, medicine or law. Despite this, there’s no shortage of wisdom pearls, which accumulated in the decades that preceded us.
One interesting phenomenon I’ve observed in myself over the years—and I’m sure there’s a name for it—is that some of these sayings sound like they must be right, even if I don’t really understand them the first time I hear them. For instance, in my post about the SOLID principles, I mentioned how the SRP’s definition—”each class should have just one reason to change”—just ticks the right boxes for me in some way that I can’t even pinpoint.
Unfortunately, just hearing a phrase and acknowledging that it kind of sounds right doesn’t do much to really make you understand the topic, right?
Then why do so many in our industry act like that’s the case? I’ve lost count of how many times I’ve seen experienced developers toss around catchphrases like this as if they’re able to automatically inject the necessary information into beginners’ heads.
In this spirit, I’ve decided to demystify one of these catchphrases that happens to be one of my favorites: “Separation of Concerns.” What does that mean and why should you care? That’s what today’s post is all about.
Continue reading Separation of Concerns, Explained
From posts that politely offer their criticisms to others that outright deem them “for dummies,” it seems that bashing the SOLID principles is all the rage nowadays.
The fact that SOLID is being criticized isn’t a bad thing. The problem is that I don’t think the arguments against it are really that good. There’s some valid criticism, but it seems that a large portion of it comes from some misunderstanding of the principles. Some people even read obscure agendas in them.
This post is meant to investigate some of the more common criticisms of the SOLID principles, offering my take on why I believe they’re not quite justified.
SOLID Principles: Some Background
In object-oriented design, the SOLID principles (or simply SOLID) are a group of five design principles meant to make code cleaner, more flexible, and easier to change. The principles were compiled by Robert C. Martin, although he didn’t invent them. In fact, these specific principles are a subset of many principles Martin has been promoting over the years.
The name SOLID is an acronym, made up of the names of five principles. Namely, these principles are
- the single responsibility principle (SRP),
- the open-closed principle (OCP),
- the Liskov substitution principle (LSP),
- the interface segregation principle (ISP), and
- the dependency inversion principle (DIP).
Martin himself didn’t come up with the acronym; rather, it was Michael Feathers that suggested it to him, several years after he was already teaching them. I’ll come back to this later because, believe it or not, the name itself is at the center of some criticisms.
Before we get to the meat of the article, I think it’d make sense to do a quick overview of the five principles so those of you who are familiar with them can get a reminder and those who aren’t can get a sense of what we’re talking about.
Continue reading In Defense of the SOLID Principles
It’s time for the second part of our series about clean architecture. As promised in the first post, we’re going to show you a sample application in C#, to demonstrate what a clean architecture implementation might look like.
Even though our sample application will be minimalist, it’s still too much for a single post. We want to keep things light and easy for you, so we’ll have to break this post into two or three parts.
Don’t worry though: at the end, I’ll connect all the dots and things should (hopefully) make sense. And all the generated code will be publicly available for you to download and study on your own.
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Continue reading Starting A Clean Architecture Example in C#