Not working for Facebook

In november last year, I was contacted by Facebook HR.
They found my background interesting and thought I might be a good
fit for an "application operations engineer" position in Palo Alto, California. (it is
basically the link between their infrastructure engineering and operations/support
teams).
I did a few technical interviews over phone with other app ops and engineers
from CA (about the Linux kernel, lowlevel userspace, mysql, memcached, networking, programming,
scalability, etc) and solved one of their optimisation puzzles.
( I picked usr bin crash. Actually I wanted to do something with thrift but I couldn't get it to compile).
The technical interviews went well but then I had
another interview which was about handling support. As I have no experience
in setting up support frameworks and procedures to hand off to separate
support teams, I was/am not good enough for this position.

Then they suggested a role as site reliability engineer for the office in Dublin, which is more about
troubleshooting, monitoring and systems management/automation.
So I did some more interviews with SRE's and engineers from the London office and
from Palo Alto. Similar subjects as before, but with more of an operations/support touch to it.
These also went well, except the last one, which was more about things less related to
high-performance/scalability such as nfs, pam and ldap.
I think I missed too many questions on the last interview. I could come up
with some excuses such as me being tired (it was the evening before our Kangaroot showcase event, and
the call being late - Facebook HR messed up a timezone conversion) but fact
of the matter is: I have little experience with such "office ;-)" stuff.

So after 8 interviews over phone (each one about 40-60 minutes), spanning
about 2 months, they let me know they would not go forward with me.
That was late december, I asked for some feedback but haven't heard from
them since.

Bottomline: it sounded quite nice but I'm pretty happy with my current life in Belgium.