If you’re over 50 and looking for a job, what are some strategies you can use to overcome ageism?

Make sure your CV has a reasonable page length. For most professionals, two pages are ideal! You don’t have much time to impress employers, so going for a lengthy paper is not a good idea. Don’t bother writing about job experiences older than 15 years, and focus on the essential parts: job title and the companies’ names and locations. There’s no need to go into details.
Note that Your CV is like a marketing document. It should emphasize what’s more relevant and recent. Instead of writing your whole career record, identify those segments in line with your current goals, and highlight them. Create a LinkedIn profile and provide its URL in your CV.
Over 90% of employers use LinkedIn to recruit new people. Not having a solid LinkedIn profile ends up with you missing out on so many great opportunities. Remember that your CV and LinkedIn profile should be consistent without being identical.