Back when I was in school, they taught us a Resume should basically be a story explaining what you did at each company, now I went to school in the 80s and 90s, and honestly what they taught us then was completely wrong for today's fast-moving industries.
A resume should be depending on your work history 1 or 2 pages at most. Leave the story out of the resume, that's what the cover letter is for.
When writing your resume, include your Contact Information, a Short Summary of what you specialize in, your skillset, and languages spoken if you are bilingual, followed by your work history.
Now, in your work history, I personally use bullet points of my daily tasks, followed by my most important contributions to the project.
After your work history, I list any open source projects I have developed or been on the development team of. Again I bullet point what I did at those open source projects.
Finally, the file name of your resume is important also. I always save mine in the format
My Name - Position Applying For so say I'm applying for a Full Stack Position, I save my resume as
Shawn Crigger - Full Stack Developer.pdf and since a lot of companies want a Microsoft Word Copy, I also save it in word format too.
For work history, I only include jobs related to the job I am applying for, if you are applying to a Full Stack Developer job, don't include the time you worked at the Bagel Factory, or the time you were an HVAC Service Tech.