"because personal development " 2) standard practices, idioms, consistency. You can't use tabs if the entire company uses spaces or use Python if it's a Java

"because personal development " 2) standard practices, idioms, consistency. You can't use tabs if the entire company uses spaces or use Python if it's a Java shop. 3) Because in most cases, an extra set of eyes can help provide real, material constructive feedback. I have little trust that any standalone developer is going to just write 'solid code'. Who has that level of self-awareness to recognize they are 'that good', let alone actually be good without help? It's a basic matter of professionalism to work with others and to be good team members, without it, we're not going to get much done. For smaller projects with very clear requirements, it matters less.