Architecture Reminders Use a different domain/sub-domain for static assets Keep your cookies short and remember the MTU size Don't overload your web servers Use out-of-band processing - Gearman or custom via ZeroMQ Don't move relational data out of a relational database Do move _huge_ non-relational tables out of your relational DB Be very very careful with foreign keys. Avoid them if possible Think long and hard about your ORM/caching strategy If you are not on PHP 5.3 yet, do it!