Sure. But I doubt it's more than an order of magnitude more difficult. Each call needs routing info (lookups over a hundred million rows a few times). It also g

Sure. But I doubt it's more than an order of magnitude more difficult. Each call needs routing info (lookups over a hundred million rows a few times). It also generates a CDR, which, in some systems, means a full transaction (insert a row, update a balance). Another way to view this: since mainframe workloads have existed for a long time, if their performance was way beyond what you can still accomplish with commodity hardware, then we should see tech companies utterly flocking to these systems. We should see IBM selling their chips all over (after all, why wouldn't Microsoft want to get in on the action?). No one wants to deal with huge fleets of servers. If they could just give IBM some money and be done, they'd do that, no? But instead it's mostly used for older, risk adverse, applications. So while I've no doubt they end up delivering solid systems, I'm skeptical that the scale is more massive than people are used to.