4 ms·

An interesting historical note is that Facebook's chat system was originally written in Erlang (https://www.facebook.com/note.php?note_id=14218138919 https://ww

An interesting historical note is that Facebook's chat system was originally written in Erlang (https://www.facebook.com/note.php?note_id=14218138919 https://www.facebook.com/note.php?note_id=14218138919), before being replaced with a C++/Java system.

gaius 13y ago
I am more interested in why they switched away from Erlang, that is the opposite of the usual story.
- biokoda 13y ago
  They had trouble finding/training enough Erlang engineers.
  - adnam 13y ago
    Tell me about it!
  - lucaspiller 13y ago
    I used to work for a company that built it's main business product in Erlang. It worked well as product, but business wise hiring engineers was the hardest part. It wasn't helped that they are based in London, where a certain consultancy snatches pretty much anyone who lists Erlang in their CV.
  - vladimirralev 13y ago
    It's hard to believe Facebook can't find Erlang engineers. May be their interview process got in the way. If you use standard algorithm/datastructures interview questions to hire Erlang devs you will have a hard time. All normal data structures in Erlang are immutable and algorithm complexity is a controversial topic there. Using Mnesia/ETS is a bit of a taboo for interviews (like using SQL on your coding task in a C/Java interview). Many Erlang devs would dismiss such questions as irrelevant and try to move on asap which is a big no-no in interviewing.
    - fenollp 13y ago
      ETS/DETS are mutable hashtables FYI.
      - _pmf_ 13y ago
        > ETS/DETS are mutable hashtables FYI. An immutable disk persistence mechanism would be a strange thing.
    - rudiger 13y ago
      Sorry, but any good programmer will know the conventional data structures and algorithms, regardless of whether they write programs in Erlang, C or some other language.
      - vladimirralev 13y ago
        It's not about knowing, it's about relevance. These data structures do not exist in Erlang in the same way. So when they ask you to code a snippet to implement a HashMap in Erlang, that will be a pretty insane task.
      - mamcx 13y ago
        That is a bad bias. "Data structures & algorithms" could be a footnote in the history of a developer, plus, which "data structures and algorithms" will you use to hire one? The ones relevant to a erlang dev are not the same to a C/embeded one.
      - gaius 13y ago
        I've never seen the point of these questions. Yes I learned half a dozen sorts in college. But in my professional career I have done sorting exactly one way: ORDER BY. Ask me something halfway relevant...
    - fbinterviewee 13y ago
      i was headhunted and interviewed for an erlang position (working on chat). i 'failed' a technical interview when my interviewer insisted i provide sample code in php, python or c++. i offered erlang, c, ruby or js and he dismissed me
- davidw 13y ago
  Bob Ippolito answers: http://erlang.org/pipermail/erlang-questions/2014-February/077763.html http://erlang.org/pipermail/erlang-questions/2014-February/0...

gaius 13y ago

I am more interested in why they switched away from Erlang, that is the opposite of the usual story.

biokoda 13y ago
They had trouble finding/training enough Erlang engineers.
- adnam 13y ago
  Tell me about it!
- lucaspiller 13y ago
  I used to work for a company that built it's main business product in Erlang. It worked well as product, but business wise hiring engineers was the hardest part. It wasn't helped that they are based in London, where a certain consultancy snatches pretty much anyone who lists Erlang in their CV.
- vladimirralev 13y ago
  It's hard to believe Facebook can't find Erlang engineers. May be their interview process got in the way. If you use standard algorithm/datastructures interview questions to hire Erlang devs you will have a hard time. All normal data structures in Erlang are immutable and algorithm complexity is a controversial topic there. Using Mnesia/ETS is a bit of a taboo for interviews (like using SQL on your coding task in a C/Java interview). Many Erlang devs would dismiss such questions as irrelevant and try to move on asap which is a big no-no in interviewing.
  - fenollp 13y ago
    ETS/DETS are mutable hashtables FYI.
    - _pmf_ 13y ago
      > ETS/DETS are mutable hashtables FYI. An immutable disk persistence mechanism would be a strange thing.
  - rudiger 13y ago
    Sorry, but any good programmer will know the conventional data structures and algorithms, regardless of whether they write programs in Erlang, C or some other language.
    - vladimirralev 13y ago
      It's not about knowing, it's about relevance. These data structures do not exist in Erlang in the same way. So when they ask you to code a snippet to implement a HashMap in Erlang, that will be a pretty insane task.
    - mamcx 13y ago
      That is a bad bias. "Data structures & algorithms" could be a footnote in the history of a developer, plus, which "data structures and algorithms" will you use to hire one? The ones relevant to a erlang dev are not the same to a C/embeded one.
    - gaius 13y ago
      I've never seen the point of these questions. Yes I learned half a dozen sorts in college. But in my professional career I have done sorting exactly one way: ORDER BY. Ask me something halfway relevant...
  - fbinterviewee 13y ago
    i was headhunted and interviewed for an erlang position (working on chat). i 'failed' a technical interview when my interviewer insisted i provide sample code in php, python or c++. i offered erlang, c, ruby or js and he dismissed me
davidw 13y ago
Bob Ippolito answers: http://erlang.org/pipermail/erlang-questions/2014-February/077763.html http://erlang.org/pipermail/erlang-questions/2014-February/0...