Velocity - Though it is heavy on the web side of things I find it to have great speakers covering good material for anyone interested in performance, scaling, metrics, monitoring, and operations in general.

Some of the Velocity 2011 Topics and Themes include:

• NoSQL
• Mobile performance
• Effective cloud computing
• JavaScript speedups
• TCP, HTTP, and SSL optimizations
• Metrics and monitoring
• Impact on the bottom line

O'Reilly Velocity happens June 14-16, 2011