Payments and messaging
WhatsApp bots, payment callbacks, and the unglamorous jobs that move an event between systems.
A walkthrough of how this kind of system works. Not the production app.
A customer sends a message or taps a paid-order template.
The provider POSTs the event. Verify the signature before you trust it.
SQS or a Laravel job so a slow worker does not drop the HTTP request.
Reply, mark the invoice paid, or open a ticket. One event, one job.