I will demonstrate a style for building Ruby web applications under conditions of extreme uncertainty with minimal resources (e.g. a typical web startup) when you want to maintain a high, sustainable rate of performance over a long period of time. This talk will feature few, if any, slides. Instead I'll dive into real applications and show you how to keep code quality high while retaining the option to change things later. I'll be demonstrating as quickly and energetically and as clear as I can the following tools and techniques: Capybara, Guard, BDD, VCR (the gem), Goliath, webmock, defensive/proactive use of database constraints,12-factor application design, proper application partitioning (your workers do not belong in the same codebase as your web app), Resque, CloudFront (with the asset_sync gem), New Relic, Papertrail, Heroku, Pound, Airbrake, and more!