Let's deploy it! Atomic No performance hit No restarts No LB removal No thundering herd Cache reuse Must be able to serve two versions of the site concurrently! Requests that begin on DocumentRoot A must finish on A Set the DocumentRoot to symlink target! Easy with nginx Apache github.com/etsy/mod_realdoc Avoid hardcoding full paths Watch your include_path setting incpath extension can resolve your include_path for you https://github.com/etsy/incpath some contraints... Version all static assets DB Schema changes need special care