Short Definition
Prompt engineering is the practice of designing model inputs so an AI system behaves more reliably for a task.
Intuition
The prompt frames the job, constraints, context, and output format the model should follow.
Technical Definition
Prompt engineering includes instruction design, context placement, examples, tool descriptions, output schemas, and evaluation-driven iteration.
Example
A summarization prompt may define audience, length, source constraints, and forbidden speculation.
Common Misunderstandings
Prompt engineering is not a substitute for system design.
Prompts should be tested against real failure cases, not only happy paths.