Ask HN: Career change from general java dev to cyber security/machine learning

I received a computer science degree ~12 yrs ago and have worked successfully in the field as programmer, team lead and dev manager. Most of my experience comes from developing enterprise apps in Java. While I've had a successful career thus far, consistently get great reviews & make a good wage, I am also getting ... bored I guess. I'm considering various options -one idea that's piqued my interest lately is furthering my education a bit (would have to do online learning) and making a transition to working in a more specialized area of comp sci such as cyber security or machine learning. I don't have much experience in cyber security (have done some pen testing/fixing of java web apps -OWASP type stuff) and have virtually no experience with AI/machine learning concepts. I just find these things fascinating. I guess I'm curious: Has anyone made a similar career change from a more general developer type of role to something like cyber security or m