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Meet Good Design

Meet Software Design — Sat, 28 Mar 2026 17:47:14 +0000

In plain terms: software that’s easy to change without breaking what’s already there.

I hope you are starting to see the enemy. Complexity makes our systems hard to understand and hard to change — and left unchecked, it only compounds. But it helps to know not just what we’re fighting against, but what we’re fighting for. What does a system look like when complexity isn’t winning? What does it feel like to work in one?

Good design has a few common characteristics. They’re worth knowing, because they’re not just abstract ideals — they’re the goals that every tool and principle we’ll cover in this series is working toward.

The first thing you notice in a well-designed system is that it doesn’t ask too much of you. The information you need is clear and present. What a component does is apparent. You can reason about a part of the system without needing to hold the entire thing in your head — remember Ousterhout’s definition: anything that makes a system hard to understand and modify. A system that overwhelms you with things to know is a complex system, almost by definition.

Closely related is consistency. It operates at two levels. Within a component, consistency means the thing behaves predictably according to its own rules — you can learn how it works once and trust that it holds. Across the system, consistency means shared standards — naming conventions, patterns, error handling approaches — that make the codebase feel like it was written by one coherent mind rather than assembled from unrelated pieces. Independence gives different parts of a system the freedom to make their own decisions, but that freedom shouldn’t extend to arbitrariness. When different parts behave differently for no good reason, every part becomes its own puzzle. Inconsistency is a form of accidental complexity — it makes things harder to understand without making them any more capable. A consistent system respects the developer’s time and reduces the number of surprises.

The next cluster of qualities all relate to change — which makes sense, because software that can’t change gracefully is software that will become a burden. A well-designed system is flexible: you can change one part without disrupting the whole. The parts are independent enough to be worked on separately, to grow at their own pace, to be improved without requiring a coordinated effort across the entire codebase.

This flexibility is what makes a system stable. Stability here doesn’t mean frozen — it means that existing functionality is protected. When you add something new, you shouldn’t have to worry about what you might be breaking. When you fix a bug, the fix should stay contained. The risk of every change should be proportional to its scope, not amplified by hidden dependencies and tangled responsibilities.

Good design is also extendable. When a new requirement comes in, you shouldn’t have to rewrite what already exists — you should be able to build on it. This is one of the most practical tests of a design: can I add to this without dismantling it? Extendability is closely tied to reusability. Components that are focused and independent can be used in multiple places and contexts without being tailored to any specific one. You write something once, and it earns its keep many times over. Every time you reuse a well-designed component, you’re getting more value out of the original investment — and you’re not introducing new places for things to go wrong.

And then there’s testability. It might seem like a separate concern — a QA thing, not a design thing — but it’s actually one of the best signals of good design you have. It turns out that code that is clear, consistent, focused, and independent is also easy to test. You can test a component in isolation, without needing to set up the entire system around it. You can verify its behavior precisely and thoroughly. And when you have that kind of confidence in the individual parts, you have confidence in the whole. Testability isn’t just a nice-to-have — it’s a consequence of doing everything else right.

All of these qualities point toward the same thing. When your design is working, making a change means going to one place. Not one function or one line of code — that’s too literal. But one isolated, independent part of the system where the concern lives, where the change can be made, where it can be understood and tested without pulling the rest of the system into view. The change — whether it’s a new feature, a bug fix, a performance improvement, or a third-party integration — stays contained. The rest of the system doesn’t even notice.

That’s the goal. It’s optimistic, and real systems are messier than any ideal. But it’s a useful test: when you sit down to make a change, how many places do you have to touch? How much do you have to understand before you feel safe? The answer tells you a lot about the health of your design.

Now that we know what we’re fighting for, we can start talking about how to get there. The tools and principles we’ll cover from here aren’t abstract exercises — they’re the specific things that make these qualities possible. Each one is a way of pushing your design closer to the system you just read about.

Meet Complexity

Meet Software Design — Sat, 21 Mar 2026 20:36:21 +0000

In the last post, we talked about complexity in broad strokes — the idea that some of it is necessary, and some of it isn’t, and that software design is largely about eliminating what isn’t and controlling what is. But complexity is worth looking at more closely, because understanding what it actually is — and what it does to a system — is what makes the fight against it feel worth having.

John Ousterhout, in A Philosophy of Software Design, gives a definition that has stuck with me: complexity is anything related to the structure of a software system that makes it hard to understand and modify. That’s it. Not a measure of how many lines of code you have, or how sophisticated the algorithm is, or how many services are running. Complexity is about how hard it is to work with. And that framing matters, because it makes complexity something you can feel — and something you can fight.

So why does it matter if a system is hard to understand and modify? That might sound obvious, but it’s because software never stops growing. Every new feature, every bug fix, every improvement is a change. If your system is hard to change, growth becomes expensive. And expensive, in the real world, means slow, risky, and eventually impossible.

There’s another dimension to this. Modern software systems are far too large to hold in your head all at once. We are not talking about a fizz-buzz or a library management system with three requirements — we are talking about millions and millions of lines of code. You’ll never see or understand the whole thing. This is normal and unavoidable. But it means that every time you make a change, you’re making it with incomplete information. You’re reasoning about a part of the system while the rest of it sits just outside your view. The less complex the system, the safer that is. The more complex it is, the more likely that the part you can’t see is about to bite you. The goal is to be able to work on a part without necessarily understanding the whole — as safely and confidently as possible.

This is easier said than done, especially as a system grows. And growth is where complexity becomes most dangerous, because software is built incrementally — layer by layer, decision by decision — and early decisions have a way of outlasting their welcome.

Think about building a house on a cracked foundation. The crack might seem minor at first — easy to overlook, easy to work around. But every wall you build on top of it inherits the problem. The floors sit unevenly. The doors don’t close right. Every room added makes the underlying issue harder to address, because now there’s more built on top of it. The foundation was the wrong place to cut corners, and by the time that’s obvious, fixing it means tearing apart everything above it.

Software works the same way. Early decisions become the foundation on which everything else is built. When those decisions carry unnecessary complexity, every layer added on top of them inherits it. What starts as a manageable system becomes something you’re afraid to touch.

Think about this every time a new feature or requirement is introduced: it will either fit naturally into your current design, or you’ll try to force it in — which happens more than we like to admit. Maybe it doesn’t seem like a big deal, or you’re already running late and don’t have time to reconsider the design. So you make it fit. You stretch the model to hold something it was never meant to. This is where a lot of the damage happens: the scope and purpose of the system grows, but the underlying design doesn’t grow with it. The complexity accumulates quietly, and the system becomes harder to work with in ways that are difficult to trace back to any single decision.

But it’s worth saying that the goal isn’t to redesign every time something new comes in — that would be exhausting and impractical. The goal is to design with change in mind from the start, so that new things can be accommodated without breaking what’s already there. But when a change reveals that the current design genuinely can’t hold it, the right response isn’t just to bolt it on and move forward. It’s to step back, revisit the design, and bring the mental model back into alignment with what the system has become. Bolting on without rethinking is exactly how complexity accumulates quietly — one small compromise at a time.

This is what complexity actually looks like in practice — not as an abstract property of the system, but as something you feel every time you sit down to work. Here are the ways it tends to show up.

You go to make what seems like a simple change. One thing. Maybe a new rule in the business logic or a label in the UI. And then you discover it’s not one thing at all. It’s the same change in five different places, or a change in one place that breaks something in another, or a change that requires you to update something you didn’t even know was related. What should have taken an hour takes a day. And the risk of getting it wrong is higher than it should be, because the system isn’t telling you everything you need to know. At this point, the system isn’t just hard to work with — it’s genuinely risky. Every change is a gamble.

What makes all of this especially difficult is that complexity doesn’t stay where you put it. Left alone, it grows. The system drifts, slowly and steadily, toward disorder. Keeping a system simple, though, isn’t a one-time decision. It’s ongoing work. It requires deliberate effort, on every change, to resist the pull toward more complexity.

Trust me — you will spend far more of your career reading and building on existing code than writing it from scratch. This is why complexity is worth taking seriously — not just as an abstract concept, but as something that will shape your day-to-day experience as a developer more than almost anything else. The good news is that once you can see it clearly, you can start to fight it. And that’s exactly what software design gives you the tools to do.

Meet Software Design

Meet Software Design — Sat, 21 Mar 2026 20:32:14 +0000

In plain terms: A plan for building software so that it’s easy to understand and change.

You know it when you see it. You may not be able to explain why, but deep down there’s a nagging uneasiness: it looks complicated, messy, and just downright hurts the soul. The worst part is when you realize you’re the one who wrote it — and even worse is when you have to work with it. Most of us have been there. If you haven’t, you probably haven’t written enough code yet, but keep going and you will.

Here’s something almost every developer eventually discovers: every project starts off great. The codebase is small, everything makes sense, and adding features feels easy. Then, gradually, something changes. Each new feature takes a little longer than the last. A small change breaks something unrelated. You find yourself afraid to touch certain parts of the code. What started as something you were happy with becomes something you dread. Somewhere along the way, the code stopped working for you and started working against you.

This is not entirely our fault. Software, by nature, is complex — and the problems we are trying to solve are complex too. But most of us have also felt the opposite: the joy of writing code that seems to “just make sense.” Code that looks good, feels good to write, and is easy to work with. Code that tells you you did something right.

That’s where software design comes in. A good design paves the way for the “good” kind of code. If you write software, you are a designer — whether you realize it or not. So if you find yourself struggling with your code, your biggest problem is almost always the design.

Why design, though? It helps to start with the goal of software, which is to help people. We do this by solving problems — problems that are inherently complex because the real world is complex.

Complexity is not entirely a bad thing. Consider the human body: it is extraordinarily complex — organs, systems, feedback loops, all working together. That complexity isn’t a flaw; it’s what makes function possible. Remove or damage one part carelessly, and the whole thing suffers. Software is no different. A certain amount of complexity is simply necessary to accomplish anything worthwhile. The problem isn’t complexity itself — it’s complexity beyond what the problem actually requires.

Like fire, complexity can be a useful resource — but untamed, it destroys the very thing you’re trying to build. And here’s what makes it particularly dangerous: it doesn’t grow at a steady pace. Fred Brooks observed in No Silver Bullet that as a software system scales, the number of interactions between its parts multiplies faster than the parts themselves. A system twice the size isn’t twice as complex — it can be many times more so. This is why a codebase that felt manageable at one stage can feel completely out of control at the next. The complexity was always compounding; you just didn’t feel it yet.

The goal of software design is finding the sweet spot: just enough complexity to solve the problem, and nothing more. It’s far easier to make things more complicated than to keep them simple. That tension is exactly where your role as a software designer matters most.

“Perfection is achieved not when there is nothing more to add, but when there is nothing more to take away.” — Antoine de Saint-Exupéry

I never fully understood that quote until I started thinking seriously about software design. Perfection, in this context, means reducing a solution to only what is absolutely necessary to solve the problem well. That necessary complexity has a name: essential complexity — the minimum required to solve the problem effectively, unavoidable no matter which solution you choose. Anything beyond that is accidental complexity: the gap between the solution you built and the simpler one that was possible.

Accidental complexity is the enemy — and its most insidious quality is how it compounds. Every new feature costs a little more effort than it should. Every change carries a little more risk and you spend more time understanding the code than writing it, more time fixing what broke than shipping improvements. Left unchecked, it grows until you’re at the mercy of a codebase that holds you hostage, protecting itself with the threat of bugs, broken builds, and endless debugging sessions.

This is what software design is actually about: distinguishing the complexity you need from the complexity you don’t, eliminating the latter, and managing the former with intention. At its core, software design is the intentional decisions about what a system is and how it is organized. It’s your plan. Not just for solving the problem today, but for how it will grow.

And like any plan, the right one depends on the situation. Context is everything. It depends on your problem, your constraints, and the trade-offs you’re willing to accept. Brooks put it plainly: software construction is a creative process. Sound methodology can empower a skilled designer, but it can’t replace judgment. The principles and patterns are tools — they sharpen your thinking, but they don’t do the thinking for you, which is exactly what makes this discipline worth taking seriously.

So before you continue on your journey, meet software design. It won’t make the hard problems easy, but it will keep them from getting harder than they need to be. And the next time you sit down to write code, you’ll have a better chance of writing something you’re proud of — rather than something you’ll dread to touch again.

Welcome to Meet Software Design

Meet Software Design — Sat, 21 Mar 2026 20:26:00 +0000

Hi, I’m a senior developer and team lead working mostly on the backend with some frontend mixed in.

I’ll be honest: college prepared me for some things, but a lot of what I know now I learned after, on the job, through trial and error, and the occasional codebase that made me want to close my laptop and never open it again. There were concepts I wish someone had introduced me to earlier — not in a textbook way, but in a real, practical, this-will-actually-matter-to-you way.

That’s what this blog is. A series of introductions to the ideas, patterns, and practices that have shaped how I think about software — things I’ve picked up over the years from experience, from great teammates, and from books like John Ousterhout’s A Philosophy of Software Design, which genuinely changed how I write code. I want to do something similar here, but from my own perspective.

The format is simple: each post introduces one concept. Meet Software Design. Meet Complexity. Meet Abstraction. Some concepts will get a follow-up that goes deeper into practice — how to actually apply the idea in the code you write every day. The goal isn’t to be exhaustive — there are textbooks for that. The goal is to give you a foothold, an honest introduction to ideas that took me longer than they should have to discover.

If you’re earlier in your career and still figuring things out, I think you’ll find something useful here.