This document discusses building machine learning infrastructure to scale data science from the lab to production. It describes two types of data scientists - those focused on investigative analytics in the lab and those building production systems in the factory. Moving analytics from the lab to the factory requires a shift from question-driven and ad-hoc work to metric-driven and automated systems. The document outlines steps to begin this transition such as choosing a good problem, logging everything, and hiring more data scientists. It also describes tools and techniques for experimentation in production machine learning.