create design diagram

[AnnySuho]

or any other informal way of identifying current key entities and relationships in the application

[AnnySuho]

for database er diagram we can use graphviz DOT. for uml not sure yet. any suggestsions? (google uml for ruby) examples:

• https://www.jetbrains.com/help/ruby/working-with-diagrams.html
• https://github.com/os6sense/xumlidot
• https://gorails.com/tool_categories/erd-uml-diagrams/tools