Sandbox mode for financial automations. Before any test that touches your CRM or billing tools, confirm in writing (Slack with timestamp) that Stripe is in Test Mode, QuickBooks is in Sandbox Company, and HoneyBook is in Test Project Mode. After tests pass, confirm in writing again that all three are flipped back to live. Sandbox-mode-stuck installs have wasted two to three client-days of “why aren't my invoices going out”.
Double-booking on calendar sync lag. Reclaim and Cal.com both write to the same calendar; a race condition can produce a double-booked slot if sync lags. Set min-notice on Cal.com to 24 hours minimum to give the sync window time to settle.
FDCPA + payment-reminder tone. If the payment reminder reads like a debt collector, you have legal exposure under the Fair Debt Collection Practices Act and state analogues. Use soft language on the first reminder. Firm up only at T+14d. Never threaten, never imply credit reporting, never call repeatedly — and review the templates with counsel if you're in a regulated industry.
Pre-screen too aggressive. Rejecting legit prospects because the classifier is overtuned is the most common Day-7 issue. Tune the classifier toward allow-by-default; the cost of a false decline is much higher than the cost of a sales pitch slipping through.