Who should own the integration layer between our systems?
You should — meaning the credentials live in your accounts, the joined data lands in a store you can read, and the mapping rules are documented in a form your next vendor could pick up. A partner can build and operate it. What you must not do is let the join exist only inside a vendor's product, because then switching vendors means rebuilding your entire history from scratch.
The integration layer is the asset
Models are rented. Ad platforms are rented. Even your operational software is, in practice, rented. The one thing that accumulates value specific to your company is the layer that knows how those systems relate: which identifiers match, which fields mean what, and what happened over the last several years once it was all joined.
That layer is small in code and large in consequence. It is the difference between changing a phone vendor in a week and changing one in a quarter.
What ownership concretely looks like
- Credentials in your accounts. API keys and OAuth grants issued under your company's admin, not a partner's personal login. Revocable by you at any time.
- Data in a store you can read. A database or warehouse you can query directly, even if a partner maintains it. Ask for read credentials on day one and use them once.
- Documented mappings. A written record of which source field became which destination field, and what rule resolves conflicts. This is the part vendors most often keep implicit.
- Exportable history. The ability to take the joined records with you, not just raw exports of each source system, which anyone could have regenerated anyway.
Who operates it is a separate question
Ownership and operation are not the same. Most service businesses should not staff the on-call rotation for API failures, credential rotation and schema drift, any more than they should staff a network operations center. Having a partner run it is normal and sensible.
The test is whether the arrangement is reversible. If your partner disappeared tomorrow, could a competent engineer pick up the documentation, the credentials and the data store and keep it running? If yes, the operating arrangement is healthy regardless of who does the work. This is exactly the standard we hold our own integration work to.
The clause worth adding to every agreement
Ask for a plain statement that your data, your credentials and your mapping documentation are yours and will be delivered in a usable format on request within a defined window. Not an escrow arrangement, not a promise of cooperation — a deliverable.
Vendors building real custom systems rarely object. Vendors whose retention depends on opacity will explain why it is complicated. That reaction is itself the answer.
Topics: ownership · data governance · contracts · integration layer
Have a version of this question about your own business?
The useful answer usually depends on which systems you run and how they're connected. That's a conversation, not a blog post.