343 karma · joined February 22, 2015
I'd be more interested in companies which sell software to end consumers/developers and open source it at the same time. Red Hat is one of the few which has done that successfully.
Correspondingly, you need far fewer engineers in your company to build and maintain custom software for such things. I am wondering whether in medium term - say the next 4 to 5 years - we are going to see an order of magnitude decrease in the number of jobs in this sector.
I would look for extensive knowledge of data structures and algorithms, operating systems, networking and databases. If you are interested in a particular domain like machine learning or web development then it pays to know a bit about that as well.
More specifically for a job hunt, you should work your way through Cracking the Coding Interview, careercup.com and leetcode.com. These have questions marked out from companies like Google, Facebook, Amazon etc.