maybe it's time to re-consider server-side inefficiency
Yeah, that's a major infrastructure change, if you've invested a LOT of time in NodeJS or DJango.
Additionally, if you're using an SQL database, you might want to consider an "efficiency re-architecture" to limit CPU utilization and I/O calls. As an example, check your 'outer join' logic to see if you're linking tables together in the primary filter query, specifically things that don't need to be linked until later. Even a 'select for update' could start with a filter that doesn't require linking any additional tables, if you design your database intelligently (and with efficiency in mind).
[this would prevent a boatload of unnecesary I/O or networking system calls, where the "fixes" for Meltdown would impact performance the most]
I've seen enough gross examples of lazy server-side code [and been tasked to fix it] for one lifetime, probably. But I'm sure it won't be the last. "Blame where blame belongs" for inefficient server-side code, because someone 'felt' that efficiency wasn't an issue. until now.