"The <g> SVG element is a container used to group other SVG elements.
Transformations applied to the <g> element are performed on its child elements, and its attributes are inherited by its children. It can also group multiple elements to be referenced later with the <use> element."
That is the most prominent tool one would use to apply "programming" or "architectural" discipline to SVG.
For instance you could make a <g> that looks like a cat paw and then <use> it to make a track of cat paws. That's more disciplined then say, "cut-n-paste" a cat paw you drew 10 times which a real artist might do, or I might do because I can always figure out how to do it with a drawing program.
Related to that is the use of CSS, which can range from beautiful code which is easy to understand towards a complete mess.
"The <g> SVG element is a container used to group other SVG elements.
Transformations applied to the <g> element are performed on its child elements, and its attributes are inherited by its children. It can also group multiple elements to be referenced later with the <use> element."
https://developer.mozilla.org/en-US/docs/Web/SVG/Element/g