I spent a few years freelancing as a PHP developer and then transitioned into python for the last 3. It's fairly easy to transition between PHP/Python/Ruby and

I spent a few years freelancing as a PHP developer and then transitioned into python for the last 3. It's fairly easy to transition between PHP/Python/Ruby and I'd suggest getting a little bit familiar with similar languages. I know that knowing a bit of all three has led me to be able to develop more quickly and cleanly. Also, more diversity in your understanding would help with your job security concerns.