Audit what happens in my app when someone starts checkout and never finishes. Look at the order records, checkout sessions, and any inventory or seat holds created at checkout start. Implement: incomplete orders have a real state (pending or abandoned, not 'failed' and never 'paid'); checkout sessions expire (the provider's sessions expire on their own; my local pending orders need their own expiry, cleaned by a scheduled job); anything reserved at checkout start (inventory decrements, seat holds, discount redemptions) is released on expiry so abandoned checkouts don't drain stock; the pending order doesn't pollute reporting (revenue and order counts should exclude abandoned records); and if I want recovery, a single abandoned-checkout email with a link back to the pending order, sent once, only to users who gave an email and haven't since purchased. Don't hold inventory indefinitely for checkouts that might finish; an hour is generous for most products, and the release job must be reliable. Don't resend recovery emails; one reminder, then stop. Deliver: the abandonment lifecycle with the cleanup job, the hold release, the reporting exclusions, and verification: start and abandon a checkout with a stock hold, confirm the hold releases on schedule and the order never appears in revenue.