Multi-agent systems interview questions
6 questions across 2 sections, in the order you would learn them. Every answer here is one that works — but an answer you have read is not an answer you can give, so use Test yourself and say it out loud first.
When more than one agent helps
Read the section that teaches thisIf this comes up in an interview
Why use multiple agents rather than one?
Mainly to keep each context small and focused. One agent doing everything ends up with the relevant material buried among everything else it has accumulated. It is a context management technique more than an intelligence one.
Then they push further
A colleague proposes five specialised agents for a support bot. What do you ask?
What one agent with good tools fails at, measured on evals. How context and decisions pass between agents and what is lost on the way. What it does to cost and latency. And how anyone will debug a wrong answer that passed through three agents.
What gets marked up. Marked up for treating several agents as a cost that must be justified by measured failures of one, with independent work that can run in parallel as the clearest case for it.
What does a multi-agent system cost you?
More calls and more money, more latency unless workers run concurrently, more failure modes, and harder debugging since a wrong answer can come from any worker or from the decomposition. Bad decomposition is the worst case, because every worker succeeds at the wrong task.
How would you decide between one agent and several?
Measure. Run the same task set both ways and compare success rate, cost and latency. Start with a single loop, because it is simpler and often sufficient, and split only when the numbers justify it.
Coordination patterns and their costs
Read the section that teaches thisIf this comes up in an interview
What multi-agent patterns do you know?
Orchestrator and workers, fixed pipelines, critic or reviewer loops, and parallel exploration where several attempts compete. Orchestrator and workers is the most common and the easiest to debug.
What goes wrong with critic loops?
Without a stopping rule they never end, because a reviewer can always find something. Cap the rounds and define what acceptable means, since quality usually plateaus after the first revision.
Then they push further
What would you cap it with?
Three things at once, because they catch different runaways: a step limit for the loop that will not converge, a spend limit for the one converging slowly on expensive calls, and a deadline for a worker waiting on something that will never arrive. Checked at the top of the loop, so a run already over its limit makes no further calls.
Two of your agents keep handing the same task back to each other. What do you do?
The safety net stops the bill, but the bug is that there is no termination condition, only a limit. Define what acceptable output is, have the critic return a structured verdict rather than prose, and accept on the first pass that meets it. If the critic never returns accept on inputs a person would accept, the critic prompt is the thing to fix, not the cap.
These are the questions for one topic. The whole question bank covers every topic on the site.