Three Control Surfaces of AI Engineering: Prompts, Context, and Harness

What you will learn

Background

The three layers at a glance

Prompt Engineering

How a prompt engineering loop works

What prompt engineering controls

Where prompt engineering breaks down

When to use it

When to skip it

Context Engineering

How a context engineering pipeline works

What context engineering controls

The RAG pattern

Where context engineering breaks down

When to use it

When to skip it

Harness Engineering

How a harness engineering runtime works

What harness engineering controls

Where harness engineering breaks down

When to use it

When to skip it

How the three layers compose

The 13 dimensions compared

Choosing your starting point

Summary

References