If PHP is putting you off considering working at Facebook, then it may be useful to know that there are many developers who hardly ever touch PHP at Facebook.

Most back-end services (ie, the systems that build your feed, or detect spam) are in C++. Java is used in some back-end services (including, for example, in Hadoop, Hive, HBase, and the messaging product) and for the Android app. Objective C is used for the Facebook app, Messenger, Camera, and so forth on iOS. Python is used primarily in the automation and operations space. You will also find a bunch of Ruby, Haskell, Scala, and so forth around.

I am not generally a fan of PHP and much of the ecosystem around it, but using it at Facebook is very different. I also would not say that time spent learning and using PHP is time wasted - the important things to learn typically transcend language, and learning anti-patterns / deficiencies is useful too. That is also why Facebook does not expect any particular language knowledge before you start/when you interview.

You are vastly overvaluing experience in a particular language or technology. None of the languages you mentioned are particularly hard for someone to pick up fairly quickly (even more so if you already know one of the others). Being a good software engineer is largely orthogonal to which languages you have experience with.

Try explaining that to startups who want rockstar, ninja, sith lords in language X. Libraries, on the other hand, do take some time to learn.

I felt the same way when I started at Facebook. The thing I've learned, though, is that your language choice is very far down the list of important factors. Most important: the problem you are solving and the quality of the engineers you work with.

Underlying your question is the idea that the specific language you work with is an investment that's critical to future success. Whether this is true depends a lot on what kind of career path you want.

I've found that lower quality jobs are the most specific about languages - "Must have 5 years of Java 1.5 or above experience" should be a huge red flag, because that place is hiring based on years-of-ass-in-chair rather than skills.

Some companies seem to be looking for specific language skills - "We're looking for great python hackers" it might say. But this is often just marketing and doesn't mean they won't take a someone who can show excellence in other ways.

There are exceptions of course - if you are doing low-level systems work, it would be expected that you know the ins and outs of C, and I'm sure there's other examples in other specialties.

One last thing: it's always useful to get experience with a range of languages, and that will pay off down the road when you have to learn language N+1. At Facebook I've written (in descending order of volume): PHP, Javascript, Python, C++ and Haskell.

PHP still runs most of the highly trafficked Web sites on the Internet.

Rails is a permanent train wreck. The other hundred of Ruby-based Web frameworks are adequate for small, CRUD-style applications. (BTW, I like Ruby. It's a neat little language.)

In the end, it's either PHP or J2EE in 90% of the cases for high-uptime, high-traffic Web destinations.

No one at Facebook is under the impression that PHP is a particularly good language, but it does the job. What really matters are a libraries and abstractions that you'll actually be interacting with. At Facebook these are leagues ahead of any other PHP codebase I've seen.

You should read what Andrei Alexandrescu has to say about the language here: http://www.serversidemagazine.com/news/10-questions-with-fac...

Unless you anticipate working for only the hottest start ups utilizing the latest buzzwords, dismissing PHP entirely might be a bit premature. It's still hugely popular with plenty of employers looking for developers with PHP experience.

I'm going to apologize in advance if any of this seems too stern or rude.

You seriously don't have the correct mindset about this. You are thinking in a way that a lot of other people share, but it's not practical. In the real world you have to learn new technologies and languages consistently. Every day something new comes out or gets improved that makes doing a difficult task easier, and people/companies that can adapt and not be left behind do well.

If I were in your position (which I guess I kind of am, I'm also college-age but I've spent just under half my life doing some level of professional programming) I would be learning EVERYTHING I can or at least everything mainstream I can so that if I come by a cool piece of code online or at work I can tell exactly what it does.

It's true that PHP isn't as a strictly written language as some of the other languages (by this I don't mean syntax, I mean that doing two analogous operations have completely different names/attribute orders in the standard library) but it's still used by tons and tons of people. PHP isn't dying. I hate the term "dying language" because there's always something else out there that's good for that each specific language.

I'm assuming that Flash is also "dying" in your POV but just today I had to whip up a quick SWF to allow copying something to a user's clipboard because it was the simplest and quickest way to allow one-click clipboard access that I could think of and I have spent time learning Flash/AS in the past so I had that knowledge.

Now, when you say:

  it seems like it might be a waste to spend time at Facebook using PHP if the rest of the tech and start-up world has moved on

I have no idea what you mean. Do you mean that Facebook not restructuring their entire codebase to a cooler and more popular language is a waste of Facebook engineers time? Or do you mean that you learning PHP to work at Facebook would be a waste of your time? I don't understand how either of these two statement could be argued so if you meant something else I'd love a clarification.

There is absolutely nothing that Facebook can not do with PHP that they could do with Python or Ruby. Any business logic can be written in a myriad of ways. And I believe to be a strong candidate for a "wow" employee after you graduate you should be able to drop head first into any codebase and at the very least quickly get a simple grasp of what's going on.

If Facebook gave you an internship today would you reject it because you've heard bad things about PHP?

Sorry about the rant, but I've spent a lot of time working to hire other developers and it really irks me when I hear something like "oh so and so's a dying language, it's useless to learn it" because it shows that you don't have the drive and love of technology that my ideal person would.

I do want to learn lots of different technologies, including PHP! That's part of the reason I read Hacker News in the first place.

But I'm doubtful of its real-world application these days. Most news I see never mentions it, but Ruby and Python are mentioned near constantly.

I'm sure working at Facebook would be amazing. I mean, it's Facebook. But if I also got internship offers at Google and other high-tech companies, then the language I use at work will factor in.

And PHP doesn't seem nearly as significant as these other languages, so then why take a job where I'll learn and use it in-depth for months when there are other languages?

You're going to be sorely disappointed when you find out that the majority of user-facing applications at Google are in Java, which you'll hear even less of on places like here.

The reason you don't see mentions of PHP all the time on places like here is that Python and Ruby are considered "hip" languages right now. Every one and their mother wants to learn it to show off how cool it is. Which is freaking awesome because the more people that learn nice scripting languages the better, but it means people aren't being driven to build new services on PHP to show off because instead of listing off 10-20 buzzword plugins by other people, you have a limited amount of mature things you can use to make a PHP application. This is not saying that Python and Ruby don't have mature platforms and extensions.

Have you done any professional programming in the past? I absolutely guarantee that even doing an short term internship at a company using a programming language you don't know, the nuances of that specific language won't be what you take away from you but rather the different ways to think about a specific problem.

Maybe once every month I face a problem at work or on personal projects where I can say "Hey, I remember this, it's a really obscure PHP fault!" versus many many times a times a day when I think "hmm I could build this as a singleton or a factory or a ....." and can use my previous experience programming in those fashions at previous jobs to figure out what the best way to do it currently is.

Learning a new language isn't about dedicating your life to it. It's about learning new methods of completing tasks, which you can almost always apply to other languages.

It's fairly easy to construct a portfolio of web applications in whatever language you want to use and/or demonstrate competency in a language (eg contribute to open source), but it's much more difficult to say you worked on an application at the scale of Facebook. That experience is invaluable and the lessons you learn there are applicable even when you move on to applications in other languages.

You should also probably look at surveys of language adoption b/c PHP has much greater market share. Hacker News is a very skewed sample.

Wow, this could be a troll.. don't know.. clever.

There are plenty of eng jobs at Facebook that require no PHP. In more than two and a half years there I wrote probably 50 lines of PHP.