# Agentic Design Patterns > Based on "Agentic Design Patterns" by Antonio Gulli & Mauro Sauco (2025) > 21 patterns across 4 tiers for building production-grade AI agent systems ## Pattern Catalog ### Part 1: Foundational Patterns #### 1. Prompt Chaining (Pipeline) Decompose complex tasks into sequential sub-problems where each step's output feeds the next. **When to use**: Task too complex fo