I've hired people from HN postings, been hired from HN postings and been contacted for contract work multiple times which I did a number of them.
The key in the 90's to getting hired is mostly the same as today, except one key difference. Overall the key is making each submission personal by highlighting your experience and training in areas it is likely relevant to the company.
The key difference is today there are so many automated tools which scan and filters resumes before a human ever sees them. So when you are looking for a position you will be more successful finding humans to send your resume to versus systems. If you are sending to HR@, or hiring@ usually it is automated (not always), which means your resume better have the keywords that HR/recruiter thought were important when they talked to the hiring manager.
In the late 90's & early 2000's the automated resume scanning was really starting to grow, so people used to keyword stuff their resume at the end usually. Now it is better to do that as bullet points & text within the role description as some of the software disfavors keyword lists from what I have seen.
I also tailor each resume slightly to highlight certain roles and de-emphasize others which helps. I never lie, just highlight what I think might be more relevant and remove things that aren't for the position I am sending to.
FWIW: as a founder or hiring manager I never use resume or HR scanning services as you lose too many good candidates. And frankly a major part of your job is building your team and if you are outsourcing that to some software you are not doing what is best for your company or team.
edit: add a word for readability