Should the fact you conducted interviews or participated in Hackathons be on SWE resume?

[ripe sun]

Should these be listed as bullet points under your previous/current employer under the "Work Experience" section on your resume? As for the hackathons, I am referring to Hackathons that your company hosted internally i.e. Capital One has monthly hackathons

Also; Is there a certain number of bullet points per employer (e.g. a "sweet spot") or is listing too many bad/cluttered?

[visual shale]

I only added one company hackathon project to my resume which I felt was a cool project but the rest I leave out.

Personally I keep it to 4 points or less for one employer but it could also depend on how much experience you have you could probably get away with less