by trod1234 | 2025-10-12 16:13:15+00:00
I agree this isn't knowledge that takes a lot. The problem is these companies don't explain why they do what they do, in fact a lot of security stuff along these lines in the past has been tight-lipped secrecy bound stuff. You can wonder, but the answer isn't out there unless you know an insider willing to break a broadly worded NDA (not gonna happen, and some are quite broad).

The idea to segment certain types of traffic to different domains isn't that new. For example segmenting certain mail servers by marketing or transactional types into subdomains was done as far back as 2010, but it wasn't explained in whitepapers until around 2016 or 2017, where there was already gathered irrefutable evidence that reputational systems had been put in place and the rules for those damaged people running small email servers who were being illegitimately blocked from delivery; for years with no recourse or disclosure just imposed cost.

Once they published the whitepapers on that, professionals were on board because they specified what they were looking for, and how it should function. Basic Engineering stuff that people who manage and build these systems need to know to interoperate.

These things need professional outreach that standardizes it in some form or another, that's not a one-off blog post imo, and that must fully specify function, requirement, feedback mechanisms, and expectations of how its supposed to work; basic engineering stuff.

The PSL is just the same thing all over again. Big Tech just starts doing something silently that directly imposes cost on others, they don't say what they are doing. Then when it becomes too costly they try to offload it to others calling for support, though if they only do halfsies in a blog post buried in noise, they are only looking for plausible deniability.

The benefit in doing this is in anti-competitive behavior.

Incidentally, while separating subdomains for email servers has been standard practice for awhile now, recently these companies once again changed the reputational weights for things, and they aren't talking. Now its a whole domain as a single reputational namespace not just breakage at the subdomain (bb.aa.com.). No outreach on that as far as I've seen.

There are ways to do things correctly, and then there are ways to do things anti-competitively and coercively. The incentives matched to the outcomes point to which one that happens to be.

How you do something is more important than that you did something in these cases.

If you as a company don't do professional outreach about such changes or standards, and you arbitrarily choose to require something that isn't properly disclosed punishing everyone that hasn't received disclosure; that in my mind is a fair and reasonable case for either gross negligence (for general intent to prove malice) or tortuous interference with third-party companies businesses.

That question which you mentioned about asking in an interview (iirc) was actually asked in an Ignite interview, but was cut out from the recordings later, and the answer was we can't talk about what other departments are doing. They may have followed-up on that elsewhere but I never saw anything related to it.

It is critically important to know the reasons why things are structured a certain way or happen; in order to be able to interoperate. This is and has been known and repeated many times since the adoption of OSI & TCP in the 80s/90s with regards to interoperability of systems.

Blindly copying what others do is a recipe for disaster and isn't justifiable in terms of cost, and competent professional's don't roll the dice like that on large projects of that caliber of expense.

This stuff isn't straight forward either. Like knowing where the reputational namespace stops, what the ramp-up time (dm/dt) is for volume metrics to warm up a server at each provider, and objective indicators associated with when you go above that arbitrarily designed rate. (hint: non-deterministic hidden states) If it takes a month to perfectly warm a new server up without reputational consequences by an insider that knows, that's extra cost imposed on the company by that platform (whom you are competing against for email services).

No disclosure means starting over every time trying to guess at what they are doing, and having breakage later when they change things.

> reddit...

A lot of professionals no longer use reddit anymore because its a bot filled echo chamber that wastes valuable time.

Moderators there often remove posts regularly for simple disagreement, conflicts of interest, or to remove access to detailed solutions or methodology.

For an example of all that's wrong there, look to that CodingBootCamp reddit. There's a guy that's a moderator there that's been, in all probability, using a bot to destroy a competitors reputation and harass them for years, attacking the owners, execs, and going so far as to harass and stalk their children; while violating the Moderator Code of Contact. Crazy and toxic stuff. ---

You can't ever meet professional standards if you don't communicate or properly disclose interop requirements when complex systems are involved.