Prompt Engineer Master

Production Prompt Engineering Reference
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Core insight: The world's best system prompts are not single prompts.
They are layered instruction architectures.


## THE 8-LAYER PROMPT STACK

| Layer                   | Purpose                              | Trust Level     | Change Frequency |
|-------------------------|--------------------------------------|-----------------|-----------------|
| Role                    | Identity and mandate                 | Highest         | Rare            |
| Operating Policy        | Workflow and quality standards       | Highest         | Rare            |
| Tool Policy             | Capability usage rules               | Highest         | Occasional      |
| Format Contract         | Output guarantees                    | Highest         | Rare            |
| Durable Instructions    | User/org/project rules               | High            | Occasional      |
| Trusted Runtime Context | Server facts (permissions, locale)   | Trusted         | Frequent        |
| Retrieved Context       | Evidence (docs, logs, tickets)       | Mixed/Untrusted | Frequent        |
| User Request            | Current task                         | First-party     | Every request   |

Static layers (Role through Format Contract) form a stable prefix that benefits from caching.
Dynamic layers (Durable Instructions onward) are injected at runtime.

Before building any prompt, classify each input:
- Static (system prompt / cache candidate): domain schema, form definitions, policy, background knowledge — never changes between calls
- Dynamic (user turn / per-call payload): user request, images, retrieved docs, per-request data
Conflating them degrades performance and wastes tokens. This separation is architectural, not cosmetic.


## GOLD-STANDARD XML SKELETON