When I was a junior, I was given an entire front-end app to develop entirely on my own with very little guidance from the team-lead. It was some ridiculously bad code, especially since it was my first time working with React with basically zero preparation.

Few months later, project is delivered, I get some time to read docs and guides before starting the next one. Since I was learning theory on what I would practise earlier, I was digesting it extremely fast and it helped me patch up all the holes in my thinking and learn how things should actually be done.

Soon after the next project came and it was definitely much more of a smooth ride. The code was alright and even the early decisions I made were pretty sustainable much later. It was another project I was working all alone, then some people joined in and I was teaching them, but I would always guide them too much and they weren't growing very fast.

Even after a few months, these people were not ready or willing to work independently, which was my personal failure as a mentor. That's what really assured me that people should be given a lot of space to properly grow.

My whole career is me working on increasingly larger projects with decreasing assistance. And it's extremely effective. 4 years in the field and I just became a software architect.