Context engineering
The craft of choosing what a model sees before it works: which files, which instructions, which data, and what to leave out.
What it tells you about a developer
Context engineering on a resume points to a developer building agent systems rather than using a chat window. The work is retrieval, data plumbing, and measurement, which is ordinary backend engineering aimed at a model.
A model only knows what it is shown. Context engineering is deciding what goes into that window: the relevant code, the house rules, examples of good output, and the results of earlier steps. Leaving things out matters as much as putting them in, because a stuffed window makes answers worse and costs more. The phrase largely replaced prompt engineering during 2025, once the wording of the request turned out to matter less than the material around it.