Every team starts signals the same way: someone finds something interesting, posts it in Slack, and says "we should track this." For two weeks, people pay attention. Then the channel becomes noise. Nobody owns the alerts. Reps stop looking.
A signal engine is different. It runs on a schedule. It monitors specific sources for specific patterns. It scores, routes to the account owner, and creates a CRM task. Nobody has to remember to check a channel.
The difference between a signal program and a signal engine is automation with routing. One depends on human discipline. The other depends on infrastructure.