"Rails" is in the title, but there isn't really anything in the article about what the advantages of using Rails for a Slack bot are. What have been people's experience using Rails for this kind of app?
Not done a slackbot (yet?), only a few small app and a large 7-yr-project, but with Rails it's really about whether or not you love Ruby. There's still Sinatra but that's about it in regards to web-frameworks.
Rails is perfect for punching out a prototype quick and heroku (which started as an online Rails-editor) make delivery very easy.
Well leveraging rails and quality plugins makes for extremely short development time. Author mentions low server load for this app so prime candidate for rails imho.