Why some DVLA digital services don't work at night

Unpopular opinion, but I think many systems would benefit from a regular "downtime window". Not everything needs to be 24/7 high availability.

Maybe not every night, but if you get users accustomed to the idea that you're offline for 12 hours every Sunday morning, they will not be angry when you need to be offline for 12 hours on a Sunday morning to do maintenance.

The stock market closes, more things should close. We are paying too high of a price for 99.999% uptime when 99.9% is plenty for most applications.

Basically this happens because the DVLA and the stock market don't have any competition. Customers in a competitive market won't be angry when you need to be offline for 12 hours every Sunday morning; they'll just switch to your competitor some Sunday, because the competitor is providing them something they value that you don't provide.

The stock markets definitely have competition. For instance Frankfurt, London, Paris or Amsterdam very much compete with each other to offer desirable conditions for investors, and companies will move their trading from one to another if it is their interest. I think the fact they close at night is a self-preservation mechanism, traders would become insane if they had to worry about their positions 24/7.