Simon Willison has published a comprehensive guide to Agentic Engineering Patterns, offering practical strategies for maximizing the effectiveness of AI coding assistants like Claude Code and OpenAI Codex. The patterns focus on fundamental shifts in software development workflows, recognizing that writing code has become increasingly inexpensive and abundant.

Key principles include establishing robust testing and QA practices, implementing red/green TDD methodologies, and ensuring the first step is always running tests. The guide emphasizes understanding code through linear walkthroughs and interactive explanations, while also providing annotated prompts for common scenarios. Willison includes a practical example of a GIF optimization tool using WebAssembly and Gifsicle to demonstrate these patterns in action.

The appendix contains a collection of prompts Willison personally uses when working with AI coding agents, offering readers immediate practical value. This resource arrives at a crucial time as developers increasingly rely on AI assistance for coding tasks. Willison's systematic approach provides much-needed structure for integrating these powerful tools into professional development workflows while maintaining code quality and developer understanding.