Who Owns Technical Decisions When Two Agencies Build the Same Product?

Imagine one agency maintains the service that sends customer data and another builds the reporting application. A customer asks for an extra field in a weekly report. Both agencies say their part can be changed, but each assumes the other will decide what happens if the field is missing.

The founder sees two estimates and a delivery date. The more important question comes before approving either one: who can decide the behavior across the shared interface, and who will make sure it works for the customer after release?

Start with the customer task. The report needs to show a field that comes from the first service. Ask both agencies to describe the current data flow, the proposed change and the conditions under which the field may not arrive. Include the product lead or support person who knows what the customer expects to see.

This conversation may reveal that the data already exists but is named differently, or that the source service cannot supply it for every customer. Those facts lead to different work. Neither estimate can resolve the business consequence if nobody states what the report should do when the field is unavailable.

Separate the work inside each agency from the decision across the boundary. One supplier can propose a format and implement its side. The other can explain how the report will use it. The company still needs someone with the authority and context to decide the shared behavior and move the choice to completion.

That person might be an internal technical leader or another explicitly authorized owner. If the choice changes spending or a customer promise beyond their mandate, the appropriate business owner must approve that part. Giving both agencies a copy of the same diagram does not establish who can accept those consequences.

Ask the suppliers to put the proposed interface in a shared record the company can access. It should identify the data, the expected behavior, the version or environment being discussed and the important unknowns. Record the alternatives and why the company selected one. Keep sensitive values and credentials out of the record.

If the agencies disagree, identify whether they disagree about a technical fact or a business priority. A small test may help with the first. A choice about a customer commitment may need the product lead or founder. Make the question and the person who can answer it explicit.

Next assign the work after the decision. Who changes the sending service? Who updates the report? Who tests a record with and without the new field? Decide how the changes will be released and what the team will do if the two sides are temporarily on different versions. Those responsibilities can be split, but the company needs a person who can see the complete path.

Do not assume that a successful test by one supplier proves the customer journey works across both components. Agree what each supplier will show and who will inspect the combined result in an appropriate environment.

Keep an internal owner connected to the operating product. After release, support needs to know where to look if a report is incomplete and which agency to contact. The company should be able to find the current decision and the relevant documentation without relying on a private conversation with one supplier.

Agree how an urgent issue is escalated when an agency is unavailable. The internal owner does not have to perform every technical task. They do need an actionable route to the people who can investigate and the authority to request a business decision when it becomes necessary.

The existing agreements may already define parts of this work. Read them alongside the operating arrangement and involve the appropriate commercial or legal owner when responsibilities or rights are disputed. A technical decision record cannot amend a contract.

A named owner also cannot resolve missing access, insufficient implementation capacity or an untested dependency by themselves. Record those gaps and assign the investigation or support needed. Keeping two agencies does not require the company to take all delivery work in-house.

For the next shared change, write the decision, the person authorized to close it, the input required from each agency and any approval retained by the company. Add the implementation owners, a combined verification and the route for an operational problem.

If no one can explain who owns one of those steps, resolve that gap before relying on the date in the two estimates. Review the arrangement after the change and update it when the suppliers or the interface change.