Submitting your resume online is definitely not throwing it into a blackhole. I applied for a G fall internship a month ago, and they sent me a coding challenge just 1 day after. I had no previous internships, only some decent projects. I'd guess it also depends on companies. I've heard that Google has a separate resume screening center where a sourcer reads each resume for like 5 minutes and then classifies it. On Glassdoor you can also see statistics as to how people got interviews, for Google it happens to be around 37% for online applications which is pretty good considering the fact that they get so many resumes and end interviewing more than 1/3 rd of them. You could search for companies which have a higher online response rate similarly. As for Linkedin , I honestly never found Linkedin to be useful, I tried linkedin premium for a month and used up all InMail credits to message recruiters but I never had a response. The best way to get to recruiters is just cold emailing them, usually it's something like [email protected] or something like that. Be polite and tell them why you're a great candidate.