In my experience with the cryptographic security space at Facebook, what happens is the security team reaches out to you and starts a conversation. You collaboratively establish the severity, acceptable mitigation options, and appropriate timeline. There might be a little bikeshedding over various degrees of ideal option (it's more fun for the crypto guys that way). They might volunteer to do the work. You review the diffs, they're good, it lands.

They're smart people and the team knows how to collaborate with random infra/product teams.

When I was there, the experience here would've been more like "you see some comms on Workplace saying this thing went live".

For a small number of people, it would look like "It's your oncall week, and you unexpectedly receive a large diff stack from a complete stranger". Most engineers at Meta won't touch anything related to C++ during their tenure there, and you can safely assume all this stuff would be abstracted away from them.

If you are on a C++ project, odds are that your experience here would be "I'm on-call and got pinged by a random person saying they were submitting a diff stack to implement this feature". Except if your project was sufficiently large, you'd probably have known about this ages ago so the diff wouldn't actually be unexpected, nor the submitter a complete stranger.

> you'd probably have known about this ages

but nobody paid attention and it falls on oncall's plate

Sure, sometimes I got a bunch of automod diffs. Sometimes it was: fix this now. It's impossible to know everything that every infra team is cooking up.

You’d be calling libraries that are vetted by the security team. Engineering at Meta is a lot like coloring with crayons. It’s very limiting but the infra does a lot for you.

This is true, but like, sometimes you're using them inappropriately. Or you've got a limited exception for performance reasons, and your replacement solution is, uh, unsound.

Do you ever eat the crayons?

Never worked at facebook, but typically at a large companies, things like this are sent with instructions on how to go about doing that, and most often just making sure your dependencies are updated so next run of automated build/deploy will pick up the change.

triage and redirect to L7+ colleague

How it really works - security team files a task to replace a crypto algorithm in your team's code and gives you a SLA deadline of 6 months. 6 months later, no one has touched it, so they escalate. Your manager says "we are short staffed" and requests an extension. They give you another 3 months and write a detailed guide on what lines to change. 3 months later everyone they originally spoke to has left the team, and the new people don't have any context. They try and figure it out but the security person has also left the team. No one remembers what the task was originally created for. A year later the service that was using the old algorithm is itself deprecated.

You forgot the multiple rounds of taskcreeper closing the task due to inactivity