Horizontal Scaling

Horizontal scaling means splitting work across many AIs running at the same time, instead of trying to make one AI faster or more powerful.

Here's an analogy. If you need to research 100 companies, giving the whole job to one employee means that person has to keep summarizing what they've already found as the research drags on. Every summary drops a few details, and eventually even the earliest findings get fuzzy. But if you bring in 100 people and give each one a single company, each person finishes a short, accurate piece of research, and all you have to do is combine the results. AI agents work the same way. An agent working alone for a long stretch loses judgment as its memory fills up, but running many agents in parallel, each handling a short task, avoids that problem entirely.

This is different from making the same AI run faster or cheaper. That approach alone doesn't change how much work a single agent can handle at once. Horizontal scaling tries to break through that ceiling by cutting the work into pieces and handing each piece to a different agent.

In the article, 'horizontal scaling' appears in contrast to 'vertical scaling.' Moonshot AI argued that vertical scaling alone — faster inference, lower cost — can't overcome the limits of a single agent, and pointed to Agent Swarm, which deploys up to 100 sub-agents at once, as an example of horizontal scaling. Contrary to a common misconception, horizontal scaling isn't simply repeating the same task multiple times — it's breaking one large task into pieces and processing them in parallel.

If you have access to a tool that can run multiple agents at once, try a request like the one below to get a feel for how horizontal scaling works.

'Split this research into 10 sub-topics, have a different agent investigate each one at the same time, and then combine the results into one report.'

It's also worth trying the same request on a regular chatbot without agent capabilities — the tasks will run one after another instead, and you won't get the same speed benefit.