Great point—finance integration is definitely one of the most pressure-filled workstreams. In my experience, the most critical burdens tend to be:
IT systems, as you mentioned, especially when financial data structures or reporting timelines differ.
Chart of accounts alignment, which can delay consolidated reporting if not addressed early.
Intercompany processes, like billing and reconciliation, which often get overlooked until they cause friction.
Day One readiness for payroll, vendor payments, and tax compliance; these can’t slip.