Professional Programmer
Public.icon
Able to reflect human-unconsciously handled information and its flow into data structures, processing, communication, and representation that can be handled by computers without excess or deficiency
Understands the established practices for writing efficient, easy-to-understand, easy-to-modify and easy-to-extend programs, reducing duplication and repetition
Information design (Information Architecture)
ER diagram
Normalization
Communication protocol design, API design
Sequence diagram
Encryption, authentication
Class diagram
Seems necessary to perform "fake play" as Daiyuu Nobori.icon says to understand the structure