@startuml
  participant User
  box "webserver: moma (webapp, deposit), webapp.staging, deposit.staging..." #LightBlue
  participant FrontendHitch
  participant Varnish
  participant Apache
  participant Gunicorn
  end box

  User -> FrontendHitch: https queries
  activate FrontendHitch

  FrontendHitch -> Varnish: forwards query
  note left: ssl termination

  activate Varnish

  alt #transparent cache hit
    Varnish -> FrontendHitch: returns result
    FrontendHitch --> User: returns result
  else cache missed
    Varnish -> Apache: forwards query
    activate Apache

    Apache -> Gunicorn: forwards query
    activate Gunicorn

    Gunicorn --> Apache: returns result
    deactivate Gunicorn

    Apache --> Varnish: caches and returns result
    deactivate Apache

    Varnish -> FrontendHitch: returns result
    FrontendHitch --> User: returns result

    deactivate Varnish
    deactivate FrontendHitch
  end

@enduml