A composable stack still needs an accountable owner.

In March, Scott Brinker published the clearest map I have read of where martech is going. The stack of boxes is dissolving into what he calls a composable canvas: one data foundation, with custom agents built on top as the real edge. Source: chiefmartec.com I do not have a quarrel with any of it. The data stays where it lives and the intelligence sits next to it, so the advantage goes to whoever can shape it to their own business.

He is right, and the market has moved his way. Some platforms can now leave your data in your warehouse, which is good. The question is where your identity rules, segments and agents live. So I am not going to spend a thousand words agreeing. I want to talk about the one thing the report names and then walks straight past.

Of the data classes Brinker lays out, the one that decides who actually owns the system is the record of why. He calls it the context graph: the decision traces, the approvals, the reasoning behind what the machine did. He treats it as architecture, a useful thing to capture on the way to real-time everything. It is not architecture. It is governance. The “what” lives in any system you care to name. The “why” is what a board, a regulator or a customer asks for when a decision goes wrong, and it is the thing almost nobody is keeping on purpose.

In Australia, that gap now has a date on it. Brinker’s report calls the context graph the keeper of the “why”. From 10 December 2026, many businesses have to disclose, in their privacy policies, the kinds of decisions they let machines make, and the kinds of personal information behind them. The Consumer Data Right keeps widening. The report describes a best practice. I am describing a legal requirement, with one distinction worth keeping sharp: the law asks for the disclosure, not for any particular architecture. The recommendation is mine, and it is blunt. The disclosure is easiest to write accurately when the logic behind each decision is yours. Owned systems still need disclosing. A document written for a global audience, and sponsored by a data platform, was never going to lead with that. It is not their deadline.

Here is where the architecture and the ownership part ways. You can assemble a composable canvas out of rented parts and it will run well. The question is where the definitions, rules and agents behind each decision live. From 10 December, a covered business has to describe the kinds of personal information and the kinds of decisions its programs use, and running them on a vendor’s platform does not move that obligation. If the logic lives in a supplier’s account, the description starts with a request to the vendor. When the logic is yours, so is the record.

Where can your team get the record?

• Supplier-managed records Access, retention and export rights agreed in the contract
• Business-controlled records Access, retention and maintenance assigned to your team

Test both: can another team retrieve and use them?

It is tempting, at this point, to reduce ownership to infrastructure: our cloud means ours. The boundary is rarely that clean. You can host a system nobody in the building understands. You can also run on a managed service while holding strong access, portable records and independent evaluation. Control is what you can do, not where the software sits. Can you retrieve the record? Can you follow the logic? Can you test it without the supplier in the room? Can you change supplier without losing the learning? Does the owner have a name? When I say own, that list is what I mean.

So I read Brinker’s report as good news, mostly. But validation cuts both ways. When the architecture is something everyone can buy, from the same handful of platforms, assembled the same way, the architecture stops being the edge. Within a year, composable is table stakes. The edge is the part you cannot buy off a shelf: the layer that decides. Your definitions, rules, segments and agents, in systems your own people run.

Everyone is about to own the same composable canvas. The only edge left is owning the layer that decides.

Wes Fischer, founder and CEO, NTWRK