From Prompt to Autonomous Agent is a practitioner’s guide to building AI systems that actually run in production – written for engineers who build things that need to work at 3am, six months after launch.The book teaches twelve levels of agentic AI architecture using a single, unbroken running example: a job failure in AWS Glue that requires a root cause diagnosis. This same system evolves over the fifteen chapters - from a single API call in Chapter 1 to a Society of Agents deliberating over a novel multi-factor failure in Chapter 12. You don’t just know what each pattern is by the end. You know what it is for, how much it costs, and what it gives you over the level below.Each chapter focuses on a single pattern: the Basic Responder, the Router, Tool Calling, Memory Augmentation, the Autonomous Agent, Reflective Self-Critique, Human in the Loop, Planning, Multi-Agent Coordination, Tool Building, Hierarchical Orchestration, and the Society of Agents. Each chapter has working code (one file, under 100 lines, no dependencies other than the Anthropic SDK) and a Failure Museum - a catalogue of real production failures with the signal, the cause, and the fix.The final section, Production and Craft, covers what most AI books entirely skip over, how to make agentic systems observable, how to protect them with cost guardrails, how to build fallback chains that degrade gracefully, and how to evaluate them with enough discipline that you know they're working before your users tell you they aren't.The book is for data engineers, backend engineers, and ML engineers who are done with demos and ready to ship. Requires Python fluency and engineering judgement. No prior knowledge of AI research, math or language models is assumed.The examples are in Python and use the Anthropic SDK because that’s where real systems live. They are based on real AWS infrastructure , EventBridge, Glue, Lambda, Bedrock, Snowflake, OpenSearch.The core principle runs through all the chapters: the right level is always the lowest level that can reliably handle your problem. This book will show you how to figure out what level that is.