What to Include
Write down everything. A CV is a record, not a highlight reel.
Include
The boring parts of every job – routine tickets, maintenance, paperwork.
Every technology you touched, even the ones you only touched once.
Problems you solved, and how you went about solving them.
Teaching, mentoring, and learning.
Volunteer work, home lab projects, talks, and open source contributions.
Do Not Trim
Leaving out the mundane work is the single most common mistake. Those entries are exactly the ones that show consistent, day-to-day capability.
See What is a Curriculum Vitae? if this feels like too much.