if you are going into power systems, this is the skill mix the industry cant find right now
quick context, i work vendor side in substation automation and we struggle to fill exactly the profile below, so take this as a market observation not career advice
terminology thing first because it bugs me: what everyone calls "digital substation" is not the substation going digital. transformer stays transformer, breaker stays breaker, primary plant does not change at all. what changes is the secondary system, protection and control and automation moving from dedicated boxes to software on servers. once you see it that way the skill question gets a lot clearer
the profile that gets hired fast splits roughly in three. nobody expects a junior to have all three, but the ones with two are already rare
protection automation and control: relay logic, fault clearing, selectivity, iec 61850 with goose and sampled values. this is the foundation and it does not go away. if anything it matters more once things run virtualized, because now you also need to understand real time behaviour
networking: process bus and station bus, ptp time sync, redundancy like prp and hsr, vlans and traffic separation. when protection is software, network problems become protection problems. most protection people are weak here
devops: linux, git, containers, ansible, ci cd, how to deploy and roll back a config on something you cannot just reboot. almost nobody in classic p&c has this and its exactly where utilities and vendors are short
ai is showing up in tooling first, config validation, automated testing, anomaly detection. not replacing protection logic anytime soon, but being comfortable working next to it will be assumed
where to start without waiting for a job: seapath from linux foundation energy is open source and runs in a vm. libiec61850 lets you play with goose and sampled values on a laptop. put a substation config in git and version it. that alone puts you ahead of most graduates
people who can talk to the protection engineer and the platform engineer get pulled into the interesting work fast. everyone else stays in the lane they started in