Scalability is the ability of a system network or process to handle a growing amount of work in a capable manner or its ability to be enlarged to accomodate that growth.
- Use cloud that has ability to launch server on demand
- Use load balancer (Amazon ELB, Rackspace Load Balancer)
- Choose the right data storage (SQL or noSQL)
- cache things
- queue up everything that doesn’t need to be done synchronously, stats, logs notifications
- Automate everything – you should be able to launch servers that self configure and get added to the resource pool automatically
- run load tests
- monitor everything – setup alerts
- separate business logic into Service Oriented Architecture