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Posted 16 hours ago · 41,926 reads

Legacy code is called legacy for a reason. It works. It's been tested in production. It's often the most reliable code in your system, even if it doesn't follow modern conventions.

The most important insight I've had in the last few years is that constraints are a feature, not a bug. When you have unlimited resources, you can solve any problem in a hundred different ways. When you have constraints—limited memory, limited time, limited developers—you're forced to think more clearly.

Systems thinking matters.

Most of the code we write is not rocket science. It's ordinary business logic, wrapped in layers of frameworks and abstractions. Sometimes the simplest implementation is the best.

Code reviews are less about finding bugs and more about ensuring that the team understands why a decision was made. The review is a conversation, not a gate.

Readability is not about clever code or terse syntax. It's about making the intent of the code obvious to the next person who reads it—which might be you, six months later, having forgotten everything.

Type systems don't prevent bugs—they just catch certain categories of bugs earlier. The real benefit is the documentation they provide about what a function is supposed to do.

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APIs are contracts. Once you publish one, changing it becomes expensive for everyone who depends on it. The cost of breaking changes compounds over time, which is why the boring, conservative choice is usually the right one.

Your future self will thank you.

Legacy code is called legacy for a reason. It works. It's been tested in production. It's often the most reliable code in your system, even if it doesn't follow modern conventions.