Crystal is a new programming language that focuses on developer productivity, type safety and execution performance. It is statically checked and compiles to native (machine) code. It combines a global type inference algorithm, compile-time macros, compile-time type introspection, automatic union types and Ruby-like syntax, allowing quick prototyping and generating efficient computer programs. It provides a Garbage Collector, uses LLVM as its backend and doesn’t run on a Virtual Machine. In this talk we will show some examples and patterns that arise from combining all these language features.