Lynn Root - Metrics-driven development [EuroPython 2015] [20 July 2015] [Bilbao, Euskadi, Spain] At Spotify, my team struggled to be awesome. We had a very loose understanding of what product/service our squad was responsible for, and even less so of the expectations our internal and external customers had for those services. Other than “does our Facebook login work?”, we had no understanding of how our services we’re responsible for were doing. How many users actually sign up or log in with Facebook? How many users have connected their Spotify account with their Uber account? Do folks even use Spotify with Uber? With a 2-month challenge period, my squad and I focused inward to establish those unanswered questions and to establish feedback loops and always-on dashboards. This talk will tell the story of how we chose which metrics are important for us to focus on, what technologies we have used and are using, and how we’ve iterated over our feedback loops to fine-tune what metrics we care about.