Stuff to do during this summer
Build your StackOverflow profile. It's a great way to get noticed by employers. The higher your reputation, the higher your chances of getting noticed
Work on your programming skills with Hackerrank. It's gonna help you a lot! Many employers use Hackerrank now to conduct technical interviews. Domains you should definitely look at: Data Structures, Algorithms, Security etc.
Get some web dev experience. Doesn't matter what platform you're into (mobile,web,VR,embedded etc), you'll encounter web technologies, period! You don't have to be a wiz, Just some basic understanding of HTML,CSS, and JS will do. Of course, you can go beyond that. The reason I'm saying this is because it's REALLY easy to get started with web dev and it's very likely that you'll end up having to build a web app at a hackathon. Plus 90% of jobs out there require SOME web experience if not a lot. There are plenty of resources out there but I'll be posting a list of web dev resources here soon!
Get really good with using Git. I am planning on getting us started with contributing to open source projects next semester.
Get familiar with using RESTful APIs. Let's face it, hackathons are API-fests and mostly RESTful API-fests. The following are a few good ones to get your feet wet (they have good documentation).
- Google Maps
Join relevant IRC channels and learn from the conversations there.
Attend hackathons which are close to you. Attend as many as you can! You will learn so much just from being and doing something there!!
Listen to some podacasts on programming topics or other topics similar to programming. There are some good podcasts on YouTube but you can choose whatever platform you want. Feel free to add other channels etc which do podcasts here.