Don't write bugs
This is so funny. I can’t even.<p>It’s true that you can write code that has no bugs that would be relevant in a programming contest. And that you can avoid the kinds of bugs that you’d find if you read your code 2-3 times.<p>But if you write code that has to live for a long time, on a lot of devices, used by a lot of people, and that gets attacked by adversaries, then you really start to appreciate the inevitability of bugs even in code that seemed flawless.