Architecture

The design of dobby is modular:

Database object acts as a black box with only execute method exposed
Each API service is defined in a separate module and only interacts with the database via this method
Each API service is pluggable, meaning dobby can run all or some of the services - as needed.
Database has swappable back-ends (e.g. using sqlite instead of dobby's engine is possible)

Use-case diagram

note: this doesn't really make sense, since Rust is not an OOP language, but the university course I'm doing this for doesn't really care.