Integration Design Checklist: Field Kit

A demo integration works because nothing fails. A durable one is defined by how it handles the unhappy paths. Work through these before and during the build.

Before any code

Name the source of truth for every shared fieldWhen two systems can both edit a field and neither owns it, they drift apart and you cannot tell which value is correct.
Default to one-way sync, with the other system as a read-only mirrorTwo-way sync creates conflicts that one-way sync removes entirely.
If two-way is required, write the conflict rule down firstRetrofitting last-write-wins or field ownership later means untangling data that has already diverged.
Plan an id mapping table linking each record across both systemsWithout it, lookups become guesses based on names or emails.

Integration Design Checklist

Before any code

Authentication and limits

Failure and drift

The rest of the kit is one step away.