Recently quite a few of my customers have been complaining about performance of their SharePoint Online sites. Where home pages take about 8- 12 seconds to load. Even Microsoft Support just tells me that it is acceptable for pages to take 8 seconds to load.
Microsoft asked me to create a new site collection and then when these sites load fast will tell you that things work as expected.
But many production sites run slower:
So what is the difference between an out of the box site collection and a production site. It took me a while to figure out. One of my colleagues showed me a pages that too 10 seconds to load even though there were only 2 out of the box web parts on the page.
The only other thing on the page was the navigation. Checking the navigation settings I found that the navigation was set to inherit from the parent site and the parent site was using Structural navigation.
When I broke the inheritance of the navigation the site loaded a lot faster. Then I enabled Managed Navigation on a single site and the page still loads fast.
Time to implement Managed Navigation using Waldek’s article across my site collections.