So if they tell you you are too old in your early 30s/40s/50s/etc. their hiring policy is fucked up in the first place, so do not worry about that, as you do not want to work for such a company anyway.

My advice is to think about the $domain (news, social-media, medical devices, bioinformatics, vision, gaming, earth-observation, automobile, chemistry, education, ...) you would like to work in and the $activity (software development, software testing, marketing, sales, support, devops, technical documentation, talking-with-humans, teaching, ...) you would like to spend most of your work time onto.

If you have clear answers to these questions it might be simpler to find potential work employees and companies and you can also make a more specialized cold-email application.