I have a PWA r shiny app deployed to Heroku via docker. I use the Golem framework for the server functions and shinyMobile for the UI. The app works great around 99% of the time. However, sometimes the server is running BEFORE the UI function, and this triggers an error, as the UI needs to run before the server, amongst other reasons because I’m using shinyjs.
The error is triggered only the first time the app is app is startet, right after the “onStart” is run, as the server function misses objects generated via the UI function (some of the shinyjs$myfunction() etc). However, as Heroku requires an app restart once daily, I get the error around once a week. The user experiences an unresponsive app until it is restarted. Usually it occurs if a user has been using the app the before the app restart, and then opens the app again shortly after the app has been restarted.

I built my shiny app {myapp} following the {golem} framework. I built my app as a package and there is an /app.R file currently deployed to posit connect. I also created a Rmarkdown document located in /inst/rmd/publishme.Rmd . This is rmarkdown generates some of the “main plots” using the functions in the package and will email them to me on a schedule.