A comprehensive guide to six core agentic design patterns for building autonomous AI systems in 2026: Reflection, Tool Use, Planning, Multi-Agent Collaboration, Orchestrator-Worker, and Evaluator-Optimizer. Each pattern includes working Python and TypeScript code using LangGraph, a taxonomy table with complexity and risk tradeoffs, and a decision framework for choosing the right pattern. The guide also covers production concerns including observability, cost control, human-in-the-loop checkpoints, and testing strategies. Key thesis: mastering composable design patterns matters more than mastering any single framework, and flow engineering has overtaken prompt engineering as the highest-leverage skill in AI development.
Table of contents
Table of ContentsWhy 2026 Is the Year of the AgentFrom Prompt Engineering to Flow Engineering: What Actually ChangedThe Core Agentic Design Patterns: A TaxonomyPrerequisitesPattern 1: Reflection (Self-Critique Loops)Pattern 2: Tool Use (Grounding Agents in the Real World)Pattern 3: Planning (Decompose, Then Execute)Pattern 4: Multi-Agent CollaborationPattern 5: Orchestrator-Worker (Dynamic Task Decomposition)Pattern 6: Evaluator-Optimizer (Test-Driven Agent Development)Interactive Decision Tree: Which Agent Pattern Do You Need?Production Considerations for Agentic SystemsWhat's Coming Next: The 2026 to 2027 HorizonThink in Flows, Not PromptsSort: