Neural networks are an excellent way of mapping past observations to a functional model. Many researchers have been able to build tools to recognize handwriting, or even jaundice detection. While Neural Networks are powerful they still are somewhat of a mystery to many. This talk aims to explain neural networks in a test driven way. We’ll write tests first and go through how to build a neural network to determine what language a sentence is. By the end of this talk you’ll know how to build neural networks with tests!