Audit my free trial flow end to end: how trials start, what happens when they end, and how the first charge works. Verify and fix: the trial has a defined length stored with an explicit end date, not a cron guess; users get a reminder email before the trial converts to paid (a few days out, standard practice and required by card network rules in many cases); the first charge at trial end is handled by the provider's subscription mechanics, not by my own scheduled job charging a card (which drifts, double-charges, and fires at the wrong time); users without a card on file who let the trial lapse get downgraded to the free tier or lose access deliberately, with the state recorded, not left in limbo; and trial abuse is limited (one trial per customer at the provider level where supported, and no unlimited trial restart by deleting and recreating an account with the same card or email). Don't silently charge at trial end without the reminder; it generates chargebacks and in some jurisdictions it's illegal. Don't implement my own billing scheduler when the provider has trial mechanics built in. Deliver: the trial lifecycle with each transition wired, the reminder email, the lapse handling, and verification in test mode: start a trial, fast-forward it (provider test clocks or a short trial), confirm the reminder, the first charge, and the lapse path for a cardless account.