Building Agent Systems

A comprehensive reference for building production AI agent systems, covering the full stack from single-agent patterns like ReAct and plan-execute to multi-agent coordination with swarm intelligence and file locking. The routing table is particularly useful: it gives you clear decision rules for when to use single vs. multi-agent architectures, with concrete thresholds like "3+ independent files" or "2+ parallel flows" to trigger TeamCreate mode. Also includes RAG pipeline design (chunking strategies, hybrid retrieval, reranking), LLM security hardening against prompt injection and jailbreaks, and evaluation frameworks using RAGAS and LLM-as-Judge. The "scale up is hard, scale down is easy" principle for choosing multi-agent upfront is solid practical advice. Treats prompts as version-controlled code and mandates eval sets before production, which is the right forcing function.