Logging framework dedicated for complex shiny apps. Different types of events can be logged (value of a variable, multi-line output of a function, result of a unit test, custom error, warning, or diagnostic message). Each event can be logged with a list of parameters that are event-specific, common for events within the same scope, session-specific, or app-wide. Logging can be done simultaneously to R console, browser JavaScript console, a file log, and a database (MongoDB). Log data can be further analyzed with the help of process-mining techniques from 'bupaR' package.