[Recorded at the May 12, 2015 Microservices Meetup in NY.] Dealing with a traffic spike amounting to half of Amazon’s traffic each day when new sales are announced is no easy matter. Michael Bryzek, co-founder of retailer Gilt Groupe, talks about the architectural and cultural evolution that took place as Gilt introduced microservices during its growth over the course of the past seven years. Transitioning from a few monolithic systems to somewhere in the range of 300 to 400 microservices today presented a lot of challenges along the way. First describing how they decided to prioritize which parts of their system to optimize by breaking it into smaller, more optimized services, Bryzek covers some of the challenges that were encountered and how they went about solving them. He also describes some of the steps they took right up until today, when they have begun transitioning to Amazon’s AWS. Successfully building a microservices architecture typically takes a strong culture of trust with teams that are empowered to do the right thing. Bryzek discusses some of the sources of inspiration they had when faced with the problem of developing trust while growing their engineering capability, and some of the other organizations whose lessons they looked to for ideas.