[traviscj]

Not sure that this is the best answer, but seems like a good use of feature flags. If the flag points to the old state, serve the old assets. If it points to the new state, serve the new assets. So make a deploy with both assets, deploy everywhere, then flip the flag.

A bit unsatisfying because it probably isn't always easy the include both assets.

Another idea (not sure if a good one) would be having the load balancers pin a certain session to a certain backend machine. Seems like this would make it better without fixing it, though: that session will still need to switch to a different set of assets when "their" server is deployed.