Code was carved in stone, it now is clay but will become water.

The title says it all. Before the era of agentic-programming software had to be designed so it could be not touched for a very long time. It was carved in stone. With the speed you can build, update and maintain features nowadays (and not even talking about parallel agents working on things) things have started to change.

Code has become some sort of clay that you can form, change, mold however you like.

Of course, it currently still costs some brain power to make changes, but my guess is that will change soon as well. Code will turn into water where it can shape even more.