The beginning of a project is often the easiest. Motivation is volatile and I've learned, most engineers (like me), prefer to start new things than fine-tune old ones.
While I've been building little insignificant sites in the last 2 years, I started working professionally on a real life project in August (2019).
I've literally interacted with code older than me during this period (C# incase you're wondering).
This has made me reflect on code reusability, extensiveness and simplicity. Writing production code is an entirely different experience.
Commercial products hardly die and the building blocks never change. You typically have to write code once and fine-tune forever.
This reality is hard for me, but what else can I say. A company can't rewrite their product any time a new grad comes with an entirely new way of doing things.
It's just not scalable and most importantly not affordable.
Part of being a good software engineer is learning patterns for writing reusable and easy to maintain code.