15 section
Design Patterns
A pattern catalog and its shadow: seventeen named moves that work, then fifteen that look reasonable and quietly cost you accuracy, money, or an outage.
What is in here
Read this section after the topic chapters rather than before — the patterns are compressed and assume you already know what a reranker or a circuit breaker does. Design Patterns gives each move a name, a when-to-use and a tradeoff; Anti-Patterns does the same for the mistakes, including the symptom that identifies each one in a running system. The Pattern Index in Reference is the one-line lookup version.
01
9 min
AI Design Patterns
Seventeen named patterns from naive RAG through Corrective RAG, plan-and-execute agents, model cascades and token budgets, each with a when-to-use and a stated cost.
patternsragagents
02
8 min
AI Anti-Patterns
Fifteen failure shapes named and diagnosed, from the God Prompt through retrieve-everything RAG to vibes-based evaluation, each with the symptom that gives it away.
anti-patternspatternsrag