Data-driven design
Describing a game's content and behaviour in data files rather than code, so designers can iterate without recompiling.
Weapon stats, enemy waves, dialogue and level layout move into JSON, spreadsheets or script files the engine reads at startup or on the fly. The point is iteration speed: a designer can tune balance a hundred times a day without touching a programmer or waiting on a build pipeline.
The price is harder debugging — a fault in data rarely yields as clean a crash trace as a fault in code — and the temptation to grow your own half-baked scripting language. Don't confuse it with data-oriented design, which is about memory layout, not about where the rules live.