Page editing slow / lists break when too many components are included

When a website page contains a large number of components (over 400), editing in the author environment becomes significantly slower.  At 600 components, we have observed a great performance loss for authors.

This will not produce a server error, but produces a terribly slow authoring experience. (The experience for the site visitor to the
published version will not be any worse than to a similarly long page made of fewer components, though super-long pages are not best practice in any case. The authoring slowdown will also be dependent on their browser, and the technical capability (processor speed, memory, etc.) of their computer.  

There is also a fixed limit of the number of times a teaser can be included in a page. This limit is somewhere between 400 and 500. So, for example, with just one list component, if you make a list that will actually try to list 500 teasers on one page, you will trigger a server error and get an error page instead of your actual content.  

We recommend authors do not put more than 400 components on each page, and less if you need to plan for growth through any dynamic elements.

We encourage you to follow best practice for website design by breaking long or very complex pages into several smaller pages.

If a long page is mandatory, build the page as a series of shared content blocks (maybe 100 components each), and then use a Shared Reference components to splice them all together on the main Web page. 

And for very long lists that display teasers (over 400 entries), break the list into several pages, either manually, or with the pagination option.