List the data that moves between applications, the decisions it supports, and what happens if it arrives late. That gives you a way to decide where real-time updates are worth the maintenance cost.
Identify the source of truth
For each important data item, agree which system owns it. If two applications show different product prices, staff should know which value applies and who can correct it.
Plan for failed transfers
Decide how the team will detect failures, when a transfer should be retried, and how to prevent duplicate transactions. Start with integrations that have a clear business impact and a recovery process you can test.
Illustrative photo by Scott Rodgerson on Unsplash.