We probably need to know about tuning and have understanding of how applications should be designed to perform well (Software Performance Engineering). We don't need to be an expert, for example, in database tuning – most companies have DBAs for that – but you need to speak to a DBA in his language to coordinate efforts effectively. Or raise concerns about performance consequences of the current application design. Unfortunately it is not easy – you need to know enough to understand what is going on and communicate effectively.

Sravan Tadakamalla