You've just written a masterpiece of a web app. It's fun, it's viral, and it's useful. It's clearly going to be "Sliced Bread 2.0". But what comes next is a series of unforeseen headaches. You'll outgrow your shared hosting and need to get on cloud services. A late night hack session will leave you sleep deprived, and you'll accidentally drop your production database instead of your staging database. Once you serve up a handful of error pages, your praise-singing users will leave you faster than it takes to start a flamewar in #offrails. But wait! Just as Ruby helped you build your killer app, Ruby can also help you manage your infrastructure as your app grows. Read on for a list of useful gems every webapp should have.