Functional & Business Analysis
Hire Business and Functional Analysts
Process, configuration and the specification behind it.
The specification decides most of the cost of a programme, and it is the part most often treated as paperwork. A requirement written as "the system should allow the user to approve" hides every question that matters: who, on what basis, what happens to the thing they did not approve, and what an auditor sees afterwards.
Analysts here are expected to produce something an engineer can build from and a tester can fail — the process as it is actually run rather than as it is documented, the exceptions people have been handling in a spreadsheet, and the data that has to be migrated and reconciled before any of it works on day one.
Business Analysts
Analysts who write the exception path, not only the happy one, and produce something an engineer can build from.
Data Migration Specialists
Specialists for the part of a go-live that decides it — extraction, cleansing, load and the reconciliation that proves it worked.
What to look for when hiring
Ask them to describe the exception path for a process they know well. Anyone can describe the happy path; the requirements actually live in the exceptions.