What common mistake do developers make with Event design, why does the mistake cause problems, and what is the safer approach?

What common mistake do developers make with Event design, why does the mistake cause problems, and what is the safer approach? One recurring problem with event design is applying it without understanding the boundary it protects. Creating events for every internal method call without identifying a useful boundary that actually benefits from decoupling. In addition, Events should communicate stable business facts rather than leaking every low-level implementation detail. Safer engineering approach: keep the responsibility in the correct layer, use the framework's supported API, validate and authorize inputs, avoid hidden side effects, and verify the behavior with tests.