It is possible to enter code directly into After Effects to, for example, make an element of the video (text, image, video, layer, etc.) react in relation to a variable.

Combine 2 text objects in one

Make a composition/ image/ text invisible as a function of a variable

Make a text display something in relation to a variable

Adapt the position of a compo/ image/ text to a variable

Adapt the box to suit the text:

Create a text-responsive rectangle

Animating with expressions