We would like the performance of the Delivery Pipeline to be able to scale dashboards with 500 jobs and load in about 30 seconds. 

About 188 jobs loads in 12 seconds, so 15.6 jobs/second

About 412 jobs loads in 104 seconds, so 3.9 jobs/second

Not sure why doubling the number of jobs causes the load time to be 8.6 times slower.

We love the delivery pipeline with its excellent user interface and features.  However, we are trying to expand our current dashboards to include more environments which increases the number of jobs from around 200 to 450.  Older versions of Jenkins would error with "Error communicating to Server!" errors.  Newer versions of Jenkins do allow the dashboard to eventually complete.

Attached is a screen recording where one of our dashboards takes over 90 seconds to load. 

We find that Firefox offers multi-CPU rendering to load faster than other browsers, attached screen recordings where taken on Firefox with a 2.4 GHz Intel Core i5 MacBook Pro (13-inch, 2019, Four Thunderbolt 3 ports).