You expose some meat(job ad), soon there are 10,000 flies on it(applicants), so out comes the Raid(screen) - the harder you spray, the less flies, but you want

You expose some meat(job ad), soon there are 10,000 flies on it(applicants), so out comes the Raid(screen) - the harder you spray, the less flies, but you want a superior fly(applicant) - what to do? Less Raid? Then evolution selects flies immune to Raid. In online search and online work you soon hire apparent good flies and a few months shows they lack buzz, = costs/time wasted. For small companies, friends of friends etc does work, but the IBM's and Meta's need swarms. You can either do detailed online tech screening with your capable people using their time, or hire a specialist company with(or who have a retained pool of expertise) to do the deep search. Twas ever thus = probationary periods etc.