By design" is a phrase that suggests that something has been intentionally created or arranged in a certain way, usually for a specific purpose or goal. Some synonyms for "by design" include "deliberately," "intentionally," "purposefully," "planned," "premeditatedly," "calculatedly," "on purpose," "with forethought," "purposely," and "accordingly." Using these synonyms can add some variety to your writing or speech and convey a different tone or emphasis. For instance, "deliberately" may suggest more emphasis on the intentionality behind the design, while "calculatedly" might suggest a more strategic or measured approach.