Data mapping is the work of deciding how information in one system lines up with information in another. A customer ID here is an account number there. A date in one format has to land in another.
It is easy to treat mapping as paperwork. In my experience it is the best single predictor of whether an integration goes smoothly.
Where integrations go wrong
- Fields that look the same but mean different things
- Business rules nobody wrote down
- Nobody owning the map after go-live