When deleting one or more components from my app, the app builder will freeze entirely for 30-120 seconds. Sometimes the freeze will last long enough for Chrome to give me the option to kill the process hanging the tab.
My goal is to use the app builder. This is putting a crimp in things.
Can you provide more info? Perhaps a screen recording?
Will work on getting a recording. FWIW, the issue is transient, but appears tied to the memory usage in the Chrome tab. A refresh or close/reopen will drop memory down to 600 - 800mb (this is in line with memory usage on a new instance of Retool's Field sales template app). Deleting components seems to increase memory usage dramatically, and once memory usage gets up over 1.2 - 1.4gb, things go from laggy to frozen.
Confirmed..
i've the same issue..
After deleting any component in my editor there are about 30 seconds of lagging
I haven't been able to reproduce this issue 
A screen recording would be helpful - as well as an app export