Crankshaft is a new compilation infrastructure for V8, Google Chrome’s JavaScript engine. By using aggressive optimizations, Crankshaft dramatically improves the performance of compute-intensive JavaScript applications -- often by more than a factor of two! In this presentation, you will get an insight into how we decide which functions to optimize and how we gather type-feedback while running your code and use that to turn the performance-critical parts of your JavaScript programs into efficient native code.