You’re in the last 2 seconds of your auction. There are 100 bidders online. Some might even be doing algorithmic bidding. The most important thing is that each bidder has the current bid price in as near to immediate time as possible. The second thing is that you can accept as many bids as quickly as possible with similar latency and response so all bidders are treated the same. Third thing is to keep auction integrity - everyone sees the same information at the same time, each bid is treated equally, bids are accepted to the last microsecond, the highest bidder wins etc etc.
Synchronising persistent state at the same time as delivering on those core auction requirements is challenging.
I think thats what @srowley and I are both saying (and apologies if I misinterpreted your reply).
I would not expect 10_000 auctions itself to be a special consideration.
