In episode 12 of the Shiny Developer Series, we begin a multi-part series with RStudio software engineer on the Shiny team Barret Schloerke! In part 1 we learn more about Barret’s journey to the Shiny team and take a deep dive into the very powerful reactlog framework to help users shed some light on what can be a confusing world of reactivity in their applications. Barret leads us through interactive demonstrations of reactlog applied to simple and complex applications to pinpoint various issues on reactive logic and the flow of information from inputs to outputs.
Resources mentioned in the episode

• {rbokeh} - R interface for Bokeh: hafen.github.io/rbokeh
• {trelliscopejs} - Create interactive trelliscope displays: hafen.github.io/trelliscopejs
• {autocogs}: github.com/schloerke/autocogs
• {reactlog} - Provides a visual insight into that black box of Shiny reactivity: rstudio.github.io/reactlog
• Demos: 
  • (Launch reactlog: cmd + F3 or ctrl + f3)
  • shiny::runApp("reactlog/reactlog-pythagorus.R")
  • shiny::runApp("reactlog/reactlog-pythagorus-broken.R")
  • shiny::runApp("reactlog/reactlog-cranwhales.R")
  • shiny::runApp("reactlog/reactlog-anti-pattern.R")

Episode Timestamps
0:00 - Intro
 0:42 - Barret’s background, how he got started with R, Shiny, and RStudio.
3:41 - Bokey, Trelliscope, Ryan Hafen
4:36 - Autocogs
5:56 - Starting with RStudio
7:31 - Introduction to reactlog
9:31 - Demonstration of reactlog
10:51 - How reactlog can help diagnose issues
11:11 - Diagnosing a Shiny app's output example
13:30 - Demo of using reactlog with a larger application
14:31 - Zooming in example
15:00 - Using the search bar
17:25 - Finding anti-patterns
23:27 - Wrapup