title: Scalable event scheduler for possibly hundreds of thousands of events
body: <p>I am trying to build a restaurant reservation application. A user can reserve a table in a restaurant ahead of time and will get a reminder 30 minutes prior. I am planning to use AWS SNS for sending the reminders. I am aware of AWS EventBridge rules, but it has a limitation of 300 rules per bus and 100 event buses per account. That makes a total of 30000 rules at any given time. A workaround can be a polling worker, which keep on querying a DB for events very 'n' seconds. Is there any event based mechanism other than AWS EventBridge which supports hundreds of thousands of events or is polling based implementation the only way forward ?</p>
  <p>Thanks</p>