I only have a very shallow understanding. I think the term 'resident' comes from actually living at the hospital. A resident was expected to care for a single patient from beginning to end. They needed to be available at all times to handle that specific patient's needs.

There are deep challenges with continuity of care. How does one person hand of treatment to another person?

Imagine you and I are both working on a project. There's only one computer, you use it from 6AM to 6PM, I use it from 6PM to 6AM. We can only work on one feature at a time. How do we coordinate that handoff every day? That alone sounds like a huge pain. With a doctor, everything can super time critical, and requires just as much depth of understanding. You may have a an understanding of something that i didn't understand in the handoff. building a project, we roll back my code talk some more and do better the next day. With doctors, maybe somebody dies.

I know it's a convoluted example. I imagine most stuff is routine and can be passed around safely. But it's only routine until it isn't, and there's no way to know up front. As much as developers hate being treated like cogs, it seems like it would make doctors lives quite a bit easier. Just seems like a super hard problem. And if you don't get it right people could die. So, like, that sucks.