You have designed a system. Explain the same architecture to a CEO, an engineering manager and an engineer. What changes?

What the interviewer is testing

Whether you can adapt to an audience, which is the skill that most often separates a senior engineer from an architect. It is also the question that reveals whether you understand what each audience is accountable for.

To the CEO

They care about: business outcome, cost, risk, time to market, competitive position.

Say: what the system lets the business do that it cannot do now, what it costs to build and to run, when it delivers, what the two largest risks are and how they are being managed.

Do not say: technology names, patterns, diagrams with more than five boxes, anything requiring a definition.

Three sentences, one number, one date. "This lets us onboard an enterprise customer in two days instead of six weeks. It costs 900k to build and about 40k a month to run. The main risk is the data migration from the legacy platform, which is why we are doing it in three phases with the first one live in March."

To the engineering manager

They care about: delivery risk, team capacity, skills, dependencies, sequencing, operational burden.

Say: how the work decomposes, which parts are on the critical path, which skills the team does not currently have, which external dependencies could slip, what the on-call load looks like afterwards, and what you would cut if the date moved.

This audience is where a design is actually made deliverable or not, and it is the one architects most often skip.

To the engineer

They care about: whether it is correct, whether it is buildable, whether the trade-offs were thought through, and what it will be like to work on.

Say: the component boundaries and why they are there, the data model, the failure modes and what happens in each, the alternatives considered and why they lost, and the parts you are uncertain about.

That last one matters most. Presenting a design as settled when it is not invites the engineer to find the flaw in review and lose confidence in the whole thing; presenting the open questions honestly recruits them into solving it.

The underlying principle

The architecture is the same; the level of abstraction and the decision the audience must make change. Ask what each person needs to decide, and tell them exactly what that decision requires.

What a strong answer adds

Noting that this is what the C4 model formalises — one diagram per level of abstraction, chosen by audience — and that the most common presentation failure is a single diagram intended for everyone, which serves nobody.