Cryptographers tend to specialize into one (or max two) of the three categories:

• Theory: understanding the limit of cryptography, what it is to be secure.
• Design: constructing efficient primitives and protocols.
• Engineering: implementing the primitives and protocols securely and efficiently.

These two abstractions above engineering in the design and theory of cryptography are indeed useful:

The process of designing a protocol (or primitive) [...] requires one to isolate and understand [...] to use, invent or combine, crypto building blocks to overcome these challenges.
To do this properly, [...] one cares about is what security properties the building blocks possess so that they can be used and combined to overcome a particular challenge.