This document summarizes several companies' approaches to microservices architecture. It describes how companies like Twitter, Gilt, and Hailo implement microservices for configuration, tooling, discovery, routing, and observability. It also notes that the microservices ecosystem is rapidly evolving, with many choices for development and operational tools, orchestration, and datastores. Next-generation applications may assemble components from a Docker Hub "app store" and leverage ephemeral, orchestrated, or database-as-a-service solutions.