Right now, we do some preloading work so that Activity Stream has some pre-existing DOM to "hydrate" once it pulls enough state together in the parent process and sends it down to the content process. I think we can take this a step further. Suppose at shut down (or after the most recent state update), we take a snapshot of Activity Stream's DOM, and persist it to disk off of the main thread. Maybe in indexedDB. Maybe in a file. Who knows. Then, at next start-up (or maybe next newtab load), instead of loading the preload DOM and hydrating with React, we load the content (text, images, everything) from the file (or indexedDB, etc). That way, we don't actually need to fire up the Activity Stream stuff in the parent process for producing the new state until the parent has some free time. This was originally florian's idea, and I think it's a good one.

(In reply to Mike Conley (:mconley) (:⚙️) from comment #0) > Suppose at shut down (or after the > most recent state update), we take a snapshot of Activity Stream's DOM, and > persist it to disk off of the main thread. It would be preferable if we could avoid adding more I/O during shutdown. Doing this during idle time would be nice.

Perhaps relevant: https://css-tricks.com/render-caching-for-react/