Three terms now compete for the same line in AI engineering job descriptions. Prompt engineering is the established one. Loop engineering entered the AI vocabulary in late 2025 and dominated developer discussion through June 2026. Graph engineering followed roughly six weeks later.
They get used interchangeably. Should they be?
The three are not competing techniques. They are three different units of control, stacked. A prompt controls one model response. A loop controls one agent’s behavior cycle. A graph controls the organization of many agents. Each layer preserves the layer beneath it. A prompt does not disappear once a loop is built around it; it simply stops being the thing typed by hand.
via MarkTechPost