Context Engineering

Deliberately designing what goes into the model's context — system prompt, retrieved docs, tool outputs, prior turns — rather than treating the prompt as an afterthought.

Example: A coding agent's context engineer trims stale file diffs from the last five turns before every call, instead of letting the transcript grow unchecked.

In practice: The term displaced 'prompt engineering' as agents got more tool calls and turns — the hard problem shifted from wording one prompt well to deciding what stays in the window at all.