Monolith
Enter the monolith. Let's have some fun by reading one of the Cambridge's dictionary definitions:
monolith: a large block of stone standing by itself that was put up by people in ancient times.
First things first: a monolith does not intrinsically signal a bad design. As we will learn throughout the book, a monolith could be a perfectly sane solution for many projects and teams. Moreover, it can even be the best solution given a certain set of constraints.
Let's get to a more focused definition of a monolithic application as defined by the Wikipedia:
a monolithic application describes a single-tiered software application in which the user interface and data access code are combined into a single program from a single platform.
However, when transposing this definition to client-side architectures, we could argue that the fact that the backend is a single-tiered application is in itself a monolith, even if the user interface is not strictly provided by the backend.