Beyond ReAct: Planning Patterns
ReAct isn't the only way to structure an agent. Compare it against Plan-and-Execute and Reflexion, and know when each is worth the extra complexity.
ReAct decides one step at a time: think, act, observe, repeat. That is not the only way to structure an agent. Two other patterns show up constantly in production systems: Plan-and-Execute and Reflexion.
ReAct is deciding your next turn only when you reach each intersection. Plan-and-Execute is mapping the entire route before you leave, and only pulling up maps again if a road is closed. Reflexion is arriving, checking whether you actually reached the right city, and turning back if you did not.
When to use which. ReAct: exploratory tasks where each observation genuinely changes what you should do next, like research or debugging. Plan-and-Execute: tasks with a knowable structure, like 'refactor these 5 files' or 'set up this deployment,' where thinking between every micro-step wastes calls. Reflexion: tasks where correctness matters more than latency or cost, like a code review agent or anything shipping to a user unsupervised. Nothing stops you from combining them: plan upfront, execute each step with a ReAct loop, reflect at the end.