An easy 40-50% of resumés and applications get dumped in the bin before they're even looked at, regardless of content. Employers simply cannot dedicate the time and man-hours to going through every application, so they cull the herd without even looking at it.
It's worse than that. If you get 500 applications and you need to get that down to 1, how many man-hours does it take? How much time will the company let you allocate to that alone?
Say you spent exactly 1 minute considering each candidate, that's 8 hours of solid resume reading right there, and that's still only a cursory glance. So you want to skim each resume as quickly as possible, and divide them into two piles. One short-list of at most 10 resumes, and 490 rejects. The goal of the first-pass is that each resume gets a few
seconds in which they're looking for
any reason to reject you.So the main trick here is to make it through the initial skimming process. For that, you need to remember that they're looking for 490 reasons to put you in the reject pile vs 10 reasons to put you in the shortlist pile.
It's a crying shame that this happens, but that's just how it goes, apparently. The trick is to try and make your stand out aesthetically as much as possible, and also just plain old saturation.
Your cover letter has to be quick and pleasing to read, only contain 100% job-relevant information, short paragraphs. Same with resume. People with mere seconds to skim your submission don't want big chunks of text to read through.
However, it's also important to repeat the wording from the job advert. Many places use automated keyword-search, to decide which resumes a human should even look at. That's why so many places are adamant that resumes must be in Microsoft Word and not PDFs because their automated resume-reading software is geared to Word documents.
So step 1 is in fact just to pick out keywords from the advert, especially the requirements section then make sure those keywords also appear in your resume and cover-letter. That gets you through the computer-assisted initial scanning phase that they use to get rid of timewasters.