Architecture Q:
If a site is required to handle 100 simultaneous page loads and 100,000 simultaneous sessions, would that be considered a high-volume site? One requiring a heavy-duty code framework to support the volume? (Assuming page loads are not data intensive)
As usual - "it depends".
Nothing is absolute; in some places/contexts your 100 / 100,000 figures will be astronomically high, in others they'll scarely be noticable.
What exactly do you mean by "heavy duty" code framework? For a high volume site the only thing you really need is efficiency: providing responses as quickly as possible whilst using the lowest amount of resources - in this context a "heavy duty" framework is irrelevant.
A heavy duty or comprehensive framework is needed for other reasons, usually managing the complexity required to meet other requirements (like providing multi-tenancey, complex caching, replication across locations, integration with other systems and the ability to easily and effectively manage, maintain, extend and configure the solution).