Building a single agent is, at this point, a solved problem. The real challenge, the one engineering teams are actively wrestling with in 2026, is getting agents to work together without collapsing into a mess of redundant calls, lost context, and silent failures that are only discovered after the workflow has already committed to a bad path.
Multi-agent systems are architecturally different from single-agent loops. They require orchestration layers, memory systems that can be shared or scoped per agent, tool registries that multiple agents can draw from, and reliable handoff protocols so one agent can pass work to another without dropping state. The engineering team evaluating these platforms is usually comparing them on two axes: how quickly they can prototype a working crew, and whether the same framework will hold up under production load when 50 concurrent agent sessions are running simultaneously.
