Mautic's way to deal with campaign triggering.

Hello guys,
I am trying to set up campaigns that need fast response time regarding the time a client will receive an response short after it interacts with my system, ex:
An user bought a product on my page, it should receive a Android push notification almost instantly after this action.

What is the properly way to accomplish this in a Mautic environment?

P.S.: I’m doing all the integration with my system using the Mautic RESTful API. I’m not intending to use forms, so that is not an option to enter into campaigns.

P.S.2: Mautic Cron Jobs are explained here: https://www.mautic.org/docs/en/setup/cron_jobs.html
They recommend setting the main Cron Jobs each spaced by 15 minutes. This time window of 15 minutes is not good for my use case because I need instant response after the contact interaction.