The probability of succeeding as an atypical programmer is directly proportional to your general enthusiasm for programming. Someone who has been constantly ha

The probability of succeeding as an atypical programmer is directly proportional to your general enthusiasm for programming. Someone who has been constantly hacking and building programs for fun on the side while working a different career, and finally thinks it might be fun to do programming for a living at 61: absolutely. However it sounds like he doesn't have a prior interest in programming. Even for someone in their early 20s I don't recommend getting into to programming for the job (in your 20s this means being a software engineer for the money, for your dad it would be they like they type of schedule/work you have). This isn't because of some ideal that "real programmers should be passionate", but because there is a reason that despite a massive rise in bootcamps it's still hard to hire devs: most people don't enjoy programming enough to do it for a living. I love programming, love computer science and ultimately prefer data science work because I don't love software engineering work for 8 hours a day. So even someone who really enjoys programming might not necessarily love software engineering. If your dad was exposed to programming in college and then spent 40 years without ever picking it up again, it's likely he doesn't really enjoy programming and even more likely that he really won't enjoy learning all the tooling and frameworks required to work as a software engineer today. tl;dr if your dad is the kind of person building a k8s cluster for fun on the weekend, or likes to hack together toy react apps in the evening: the he absolutely could transition. However it's fair more likely that he currently likes the idea of being a programmer much more than he would the actual work.