Interview. A seven-person team wants to use a managed message queue that the platform does not list as approved. The company has an enterprise architect, a platform team, and team leads. Who should make the call, and under what rule?

What the interviewer is testing

Whether you know that architecture roles differ by scope of decision, not by seniority, and whether you can state a rule for who decides. The strong answer is not "the most senior person".

The reasoning

Use two properties of the decision: how many teams it binds, and how costly it is to undo. A queue used by one team behind an internal interface binds one team. If the team later swaps it, the work is bounded by that team's own code, perhaps a few weeks. That is a reversible, local decision, so it belongs to the people who carry the pager for it.

The platform team gets a short review because it owns the operational guardrails: the security baseline, cost tagging, how access is granted and how it is monitored. A review of one to two days is the right size (an archetype: a retailer with 11 teams and one architect, where three-day waits per approval meant teams stopped asking). Rule: local and reversible within about a month means the team decides. It is a consultation to catch something like "this region is not allowed", not an approval gate.

The enterprise architect owns decisions that bind many teams or are expensive to undo: the identity provider, the cloud account structure, the event format shared between domains. If the queue became the shared integration backbone for ten teams, the decision would move up.

Why the other options fail

• The enterprise architect approves everything. Central approval for local decisions turns one person into a queue. If eleven teams each wait three days, the architect becomes the bottleneck and teams route around them with unreviewed choices.
• The CTO decides. The CTO's attention is for decisions that move the whole company. A queue for one team does not qualify, and escalating it trains everyone to escalate.
• A company-wide vote. Voting spreads a decision across people who will not operate the queue and cannot be held responsible for it. "May eventually depend" is speculation, not a present fact.

When this is the wrong answer

If the queue carries regulated data such as payments or health records, or if the team is new and has never run one, escalate for review sooner. Scope can rise when the data is sensitive.

Common weak answers

• "It depends." Name the two properties above, or you have said nothing.

What a strong answer adds

Write the decision down in a short record naming the revisit trigger: for example, review again if a second team starts consuming from this queue.