Chad Fowler has written a really ineresting book. Don't want to lose you software developer job? Need to guess where to go next? Afraid of changes and risks?
There is no absolute answer but there is an idea. Look around, try things, communicate with people. Do the things you are passionate about!
I am not always agreed with the author but there are some pearls of bright thoughts in his words. It is not so lengthy but extremely worth reading.