Heh, I'll chime in as I did residency at a busy program and advanced my coding skills on the side. Even working 80hr+ weeks you find downtime. Some of that you use for sleeping and studying. With whatever's left, some of my co-residents liked to read. Others had sort of social lives outside the hospital. For me, I coded with most of my freetime. It helped scratch an itch-- problems are solved with 100% certainty, errors can be found with testing preventing many mistakes before they actually affect people, you can build something with your creative juices and get a level of independence not possible in medicine... The list goes on. But my point is, residency is demanding, but you still have a little downtime here and there.

I did a prelim-surgery intern year. The hours are worse than medicine, but there are way less "mandatory" activities (no lectures, no endless rounding, etc.). For the most part, you're on the floor waiting for pages. I used the time between pages to write code.

Now I'm a radiology resident and have much more time.

There is time for life outside of residency. My wife started residency with a 5 month old and had another child half way through, this delayed her graduation a total of 4 weeks.

I have a friend who is a resident and is the mother of 2 young children. That’s way more work than being a software developer. You find a way.