01SILENT
Syncs fail and nobody finds out for weeks
A webhook endpoint times out, a token expires, a queue backs up, and the first symptom is a customer asking about an invoice that never got created. Without dead-letter queues and alerting, every failure is discovered by accident.
02REKEYING
Your ops team is the middleware
Orders re-typed from Shopify into the CRM, payments copied from Stripe into QuickBooks, call notes pasted by hand. Double entry burns hours daily and guarantees the two systems drift apart anyway.
03SPRAWL
Forty Zaps deep, and nobody owns any of them
Zapier and Make are great until they become the architecture. Undocumented scenarios built by people who left, per-task pricing that climbs with volume, and no retry story when a step fails mid-run.
04CONFLICTS
Two systems both think they are right
The CRM says the customer moved; billing still ships to the old address. Without field-level ownership rules and idempotent writes, every two-way sync eventually creates duplicates and overwrites good data with stale data.