If you work in web development long enough, odds are you’re going to discover that your strength lies within writing code or designing a site. It’s possible to be good at both – I’ve seen it in rare cases – but it’s more common for someone to be strong in one area or the other.
As easy as frameworks like Bootstrap, Foundation, 960gs, and so on have made it for us to build layouts against a grid, it has not – thankfully – removed the need for designers (of course, that was never their intent, anyway).
The reason I bring this up is because years ago, a good friend of a mine – a designer, to be clear – would jokingly say that I was pixel approximate.
And he wasn’t wrong.