Faster Rails: How to Check if a Record Exists - Semaphore
Link: Faster Rails: How to Check if a Record Exists - Semaphore: "If your Rails app is getting slower, here are some tips on how you can make your Active Record queries faster."
Fearless Rails Refactoring
Link: Fearless Rails Refactoring: "In Fearless Refactoring: Rails controllers I'll teach how to improve your Rails controllers in a quick and safe way. This is step-by-step guide so you won't feel lost. Every step is described in every detail, with code changes. All of that, so that you can safely refactor your codebase, even without a full test coverage."
Features - Recurly
Link: Features - Recurly: "Recurly provides enterprise-class subscription management for thousands of businesses worldwide."
Fermat's Library | Von Neumann's First Computer Program annotated/explained version.
Link: Fermat's Library | Von Neumann's First Computer Program annotated/explained version.: "Fermat's Library is a platform for illuminating academic papers."
Fibers Are the Right Solution
Link: Fibers Are the Right Solution: "Good description of how to use fibers in ruby."
Finite State Machines are dead. Long life Behavior Trees
Link: Finite State Machines are dead. Long life Behavior Trees: "Very nice explanation of behavior trees"