According to constructor theory, the most fundamental components of reality are entities—“constructors”—that perform particular tasks, accompanied by a set of laws that define which tasks are actually possible for a constructor to carry out.
More generally, we could call these entities "objects", the tasks that they perform "methods" and the set of laws that define the available methods "interfaces".
There, the grand unified theory of object-oriented software design and quantum gravity!
Einstein would never have guessed that the universe is written in Enterprise Java.