This post isn’t technical, it doesn’t cover specific design patterns or advanced techniques. It’s more about stepping back and thinking about how complexity shows up in everyday coding. I wrote it to reflect on the kinds of questions I try to ask myself when writing or reading code, to be more thoughtful about structure, clarity, and how things evolve over time.
When I was learning to code, the goal was simple: make it work. In school projects or small personal projects, once the program ran and the output was correct, it felt like the job was done.
But as I started working on larger systems, especially with multiple engineers involved, I began to notice something: even when the code worked, coming back to it later was confusing. Small changes would break things unexpectedly. Features that sounded simple ended up being surprisingly messy to implement. I started realizing that writing code that works isn’t the same as writing code that lasts.
This is where the idea of complexity enters the picture. As systems grow, complexity builds up, and it quietly becomes one of the biggest challenges in software development. It makes code harder to understand, slower to modify, and more fragile over time.
“Complexity is anything related to the structure of a software system that makes it hard to understand and modify the system.”
— John Ousterhout, A Philosophy of Software Design (2018)
This post is just me trying to reflect on what I’ve started to notice about complexity. I'm still figuring it out, but writing this down helps me make sense of the patterns I'm seeing and the habits I want to build going forward.
The Cost of Ignoring Complexity
At first, complexity doesn’t seem like a big deal. The code works, the tests pass, and features get shipped. But slowly, things start to drag. Small changes take longer. Bugs are harder to fix. New team members (or even future-you) need more time to understand how things work.
These issues don’t show up overnight, they creep in. But if you pay attention, there are early signs.
Change Amplification
Sometimes, making a small change in one place means updating five other files, multiple tests, and maybe even other services. A small rename turns into a mini refactor.
This is called change amplification, and it usually means parts of the system are too tightly connected. It makes even safe changes feel risky, and slows everyone down.
High Cognitive Load
When things are too coupled, full of edge cases, or just hard to follow, it takes a lot of mental effort to get going. That’s what people mean by high cognitive load, you have to keep too much in your head at once.
Unclear Change Points
A bug shows up in one place, but the root cause is somewhere else. Or a new feature needs to touch several parts of the code, and I’m not sure which one should be updated, or if I should add something new.
Early Habits That (I Think) Help
I'm still learning, but here are some habits that seem to help reduce complexity, or at least make it more manageable.
Try to Keep Boundaries Clear
Even in small projects, I’ve started paying more attention to what belongs where. A function should do one thing. A module should have a clear role. When boundaries get fuzzy, everything gets harder to change later.
Read Code to Understand Design
Whenever I’m working in an unfamiliar part of the codebase, I try to slow down a little and ask: why is it written this way? Not just how it works, but what the intent might have been.
Doing this regularly is helping me build a kind of intuition for what “clean” or “messy” really means in context.
Understand Tradeoffs (Not Just Rules)
I’ve come across a lot of advice like “keep functions short” or “don’t repeat yourself.” These are useful, but I’ve also seen how following rules blindly can sometimes make code worse.
What I’m starting to realize is that most decisions are tradeoffs. It’s not about always doing the same thing, it’s about thinking through the consequences.
One question I’ve started asking myself more often: will this make the next change easier or harder?
Complexity Feels Like a Design Problem
One of the most valuable lessons I’m learning is that complexity isn’t usually caused by “bad code.” More often, it comes from design decisions that were made under pressure, with limited context, or simply as the best idea at the time.
Code tends to grow around real-world constraints: deadlines, changing requirements, evolving teams. Sometimes the structure doesn’t keep up, and things start to feel messy or hard to change.
What I’ve started to realize is that complexity is often a design problem, not a personal one. It's about how pieces fit together, and how decisions made early on affect everything that comes later.
Final Thoughts
Complexity is part of the job. It can’t be avoided entirely, but I’ve learned that it can be managed. And the earlier you start noticing it, the more control you have over it.
Top comments (0)