It's often too late to overhaul you systems when performance becomes a serve limiting factor. By that point things like data format are already set in stone. Th

It's often too late to overhaul you systems when performance becomes a serve limiting factor. By that point things like data format are already set in stone. The whole "premature optimization" was originally about peep-hole stuff, not architecture-defining concerns, and it's really sad to see it misapplied to "lets store everything as json and use O(n²) everywhere and hopefully it will be someone else's problem".