Planning and "extreme care" makes sense if you're building a bridge. Professional software engineering is more like a demolition derby. If you want to be successful you should focus on building fast and breaking things. It wouldn't make sense to blow up a bridge right after you've constructed it, but with software you can do just that. For example, I was just using American Fuzzy Lop a moment ago to break my symbol demangler. It was able to find eight ways to make it crash in a minute. So I fixed all those and let it run for a couple hours and it found another. Tools like this are a superpower. It's also fun to write torture tests and DDOS your own infrastructure. If you don't break it then someone else will.