Main file is src/clj/servus/engines.clj, it contains definition of the workflow, everything else is support/framework code to make it work.
Copy profiles.clj.example to profiles.clj.
Start REPL
lein repl
Invoke sample run of fetching data
(servus.core/login "user@dev-ed-sf-org.com" "your-password")
Load changes (and restart state) after changing code
(reset)