Much would depend on your actual job role, but much usually centered around the topic of "keep it working", today and tomorrow.
Much network education centers around designing new build outs, but that tends to be rare. Often the closest you come to that is doing a major equipment refresh but those generally keep much as it was just using some newer network devices.
As you asked about senior engineers, their projects are usually bigger in scope, possibly directing, and mentoring, junior engineers, and troubleshooting more difficult issues.
