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
Same issue for me, whenever I delete a component in the mobile app builder it crashes and if you try to refresh the page you get 404. I have to close the tab, go back to Retool home and edit the app again. It's a bit of a pain!
I also noted this, task manager shows high memory usage for Chrome whenever this happens
Thanks for reaching out, @Spike_Patching! We've never been able to reproduce this behavior, so I'm definitely interested in taking a closer look. Is this happening consistently for you? And is it limited to a specific app? If so, it might be helpful to see a JSON export. Regardless, it would be great to see you in Office Hours so that we can take a closer look!
Are you still running into this, @Spike_Patching?