Who's to say 'she' isn't a composite or fabricated anyway?
I would hope it's supposed to be anonymous to Facebook - after all, there were some fairly frank discussions on topics that aren't exactly public knowledge (e.g., Facebook tracking clicks and other little bits of things that really should be revealed by PR, not an employee in an unsanctioned conversation).
"Who's to say 'she' isn't a composite or fabricated anyway?"
Well, in that case the author never visited Facebook's offices - that's the detail that gives away the employee's identity. Given the level of detail gone into by the author, I doubt this is fabricated.
It would probably be better for everyone if it were, though, because he just made a real big boo-boo that will probably cost someone their job.
Maybe not because the information she gave was all that important (although the HPHP thing certainly is an interesting piece of information), but to make an example to other employees about babbling on about the internal workings of their enterprise.
Chief Privacy Officer Chris Kelly might be paying her a visit shortly.
Except that the employees description of the differences between "scripted" and compiled languages leads me to think that this person doesn't really know much about programming languages.
I get the feeling the PHP is probably compiled into some C or C++ format. The speed increase would work wonders for the production server, and if you didn't change HPHP too much from regular PHP, you could still run interpreted for development.
For scaling, I wouldn't be surprised if we started seeing hybrid models like this in the future.
Bonus: I'm also certain they have their own front-end engineering which is speeding up javascript. Nearly everyone else does, and getting that 0.5s page-load will certainly need this boost.