The really short answer is "how to code".

Forget technologies; forget grades. At best, they will get you in the door for an interview. They won't make your a productive employee.

If you can produce working, deployable software on your own, then you will succeed. Not that many people can, honestly. If you aren't sure if you can hack, then pick a problem and solve it. If at the end of a week you can give your software to someone else and have them use it successfully, you should be fine.

Everything else is fluff, and can be learned on the job. If you can hack, you'll do fine.