Cron vs systemd daemon: which one for Node.js?

On the same machine, two Node.js scripts run in the background. The first publishes to dev.to at 9am and LinkedIn at 10am — a cron, three lines of config. The second watches a job queue every 30 seconds, keeps state in memory, and reacts to user interface actions within seconds — a daemon supervised by systemd. Same language, same server, apparently the same goal: run tasks in the background. Yet the choice is different. It's not a matter of taste or habit — it's that the two problems only look