I'm not sure. I think that the problem this time won't necessarily be software, (I remember at the height of Poloniex where there were entire hours where only bots could trade through API calls..), but rather support staff to handle tickets.
As you said, after the burst most of these people probably got laid off, and now with a sudden increase in interest, it's probably going to take some time for exchange to decide whether or not they need to rehire some of these people, or not. It seems to me that Binance & Bitmex have really "upgraded" their systems to prevent lag et al, (so far anyhow).
Which will most likely be pretty visible in the response times for support tickets & KYC verification. I'm not sure how it is nowadays on most exchanges, (such as binance), but especially tickets were extremely hard to get an answer on on Bittrex/Polo.
But who knows, maybe this is just a suckers rally for all the "HODLERS" who bought in @ 5 digits to unload their dogshit unto the bitcoin price, and crash it within a matter of days. We'll see.
I'm certainly not expecting this to be
it, which is what makes it all the more disheartening. This is a couple of days of excitement, which'll probably fade as quick as it came, and the company above is reporting too much of a load, though I suspect they're fundamentally a bit shit.
If in future there's several months of ever increasing heat again it's going to look dire going on the odd hint we can pick up like this.
I think it's always been more staff and the demands on their time rather than software, though that's often been an issue too.