1. What is standard, configured or custom?
Ask suppliers to label every important capability. The distinction affects cost, upgradeability, delivery risk and your future dependence on specialist support.
2. Who owns each integration?
Name the party responsible for design, build, testing, monitoring and support. An API existing is not the same as an integration being delivered.
3. How will data move and be reconciled?
Migration needs ownership, acceptance criteria and a plan for exceptions. Payments and finance flows also need an agreed source of truth.
4. What must your team change?
A platform can be technically capable and still fail operationally. Understand new roles, processes, training and ongoing administration.
5. What happens after launch?
Clarify support boundaries, release management, service levels, data access and exit arrangements before signing—not when a problem occurs.