Software Complexity

Have you ever seen a project turned into a monster over time? Hard to understand, difficult to maintain? If so, I highly recommend Peter van Hardenberg’s talk - Why Can't We Make Simple Software?

The author explains what complexity is (it's not the same as difficulty!), why software gets so complicated, and what we can actually do about it.

Common reasons for complex software:
✏️ Defensive Code. Code that starts simple with implementing some sunny day scenario but grows over as more edge cases are handled. Over time, it turns into a mess with too many execution paths.
✏️ Scaling. A system designed for 100 users is really different from one built for 10 million. Handling scale often adds layers of complexity.
✏️ Leaky Abstractions. A well-designed interface should hide complexity, not expose unnecessary details. (A good discussion on this is in Build Abstractions not Illusions post).
✏️ Gap Between Model and Reality. If a software model isn't actually mapped to the problem domain, it leads to growing system complexity that really hard to fix.
✏️ Hyperspace. Problem can multiply when a system has to work across many dimensions—different browsers, mobile platforms, OS versions, screen sizes, and more.

The software architecture degrades over time with the changes made. Every change can introduce more complexity, so it’s critical to keep things simple. Some strategies to do that:
✏️ Start Over. Rebuild everything from scratch. Sometimes, it is the only way forward if the existing architecture can't support new business requirements.
✏️ Eliminate Dependencies. Less dependencies the system has, the easier it is to predict system behavior and make impact analysis.
✏️ Reduce Scope. Build only what you actually need now. Avoid premature optimizations and "nice-to-have" features for some hypothetical future.
✏️ Simplify Architecture. No comments 😃
✏️ Avoid N-to-M Complexity. Reduce unnecessary variability to limit testing scope and system interactions.

Complexity starts when interactions appear. So it is about dynamic system behavior. Watching this talk made me reflect on why systems become so complex and how I can make better design decisions.

#architecture #engineering