I can write sort algorithms that are nlog(n) or n^2. Both pass functional tests. I can write code that reinvents the wheel, instead of using the solid library

I can write sort algorithms that are nlog(n) or n^2. Both pass functional tests. I can write code that reinvents the wheel, instead of using the solid library I've never heard of. I can do things in non-idiomatic ways that testing and linting will never catch.