Even discounting external changes, any reasonably complex system needs maintenance because time moves on and new interactions happen.
How many SSL certificates (internal or external) need re-issuing per month? Some of that can be automated, but in an organization as large as complex as Twitter some will be bespoke and manual, and a code freeze won't stop the clock.
How many new CVEs per month apply to Twitter's services and tooling? How many race conditions or other bugs are lurking, just waiting for the right time or traffic pattern to emerge? Twitter can't freeze inbound traffic without dire consequences.
Twitter is like your car, except that it's always running.
Ugh, Paypal is still the worst. My transaction got flagged; maybe they think "DHCP" is some new street drug?
I really hope he doesn't have trouble withdrawing the funds. Paypal is known for freezing funds, sometimes for years.
From their email:
> On March 16, 2021, you sent a payment (xxxxxxxxxx ) for the amount of $xxxxx for "DHCP and DHCPd were significant in my early career. Best wishes." Please provide the following information:
>
> • An explanation of the reference to "DHCP ."
> • The purpose of this payment, including a complete and detailed explanation of what is intended to be paid for.