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. M

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.