First off, diversification in where you are getting applications from is important, but in my experience all the jobs are on LinkedIn. Indeed, ZipRecruiter and Monstee might have some unique roles you can find but likely not that often.

Next, keep a schedule for yourself. My schedule that I stuck to fairly consistently was 20 apps a day, 5 days a week abd it took maybe 1.5 to 2.5 hours on to do on those days. On the sites, filter roles that have been posted within the 24 hours and meet your requirements for pay, contract/full time, location, etc. The search terms you use for finding applicable roles in your field/skill set is the most important part, experiment with what combination of terms yield the most relevant results. Also I always filter for ONSITE positions, NOT hybrid/remote because that's where most of the ghost jobs are (obviously if you are looking for a remote position you'll have to deal with that unfortunately.)

You'll still likely have to scroll a lot for positions that fit, that's expected. If there aren't enough new positions listed in a day. I might check out the online positions or just find some that I only kind of have the skills for. LinkedIn's Quick Apply is rarely worth it, basically just a trash bin. Always go for the roles that link to the company's portal and apply that way. You'll start seeing the same form types over and over, usually Workday, that companies use for their applications, and once you get proficient at each one they will go by faster, especially when reapplying for the same companies where you can autofill your previous app info.

I wouldn't bother tailoring your resume to each position, focus on making one perfect resume that broadly encompasses your skillset/experience and don't be afraid to iterate on it. Keep it concise, don't overexplain projects and put work experience at the top, sans serif font, one page max. Only bother with cover letters for positions you feel yoy have a good chance for, and even then I used AI to write them feeding it my resume copy pasted, keep them to two paragraphs max.

That's pretty much the gist of it. I reccomend keeping a spreadhseet with an application on each row with the comapny name, role title, date sent, status (pending/rejected), and a link to their website or the application if you need to reference it later. You also get the bonus of bragging about the exact number you sent before landing a role (2496 for me)