If you want recommendations on what to avoid, an 8 page resume that starts out by listing your high school summer job in the 1960's is the best anti-example I've seen.

I was taught to leave the month off your start and end dates of previous positions when applying for a job. Still don’t know if this is a good idea or not, but at the very least it opens up another dialog tree with potential employers. Seems to have worked fine for me, but who knows. The rationale was “it’s less information to parse”. Might be just a superstition.

Interviewers always ask for more specifics anyways, which is good because you can use that as an opportunity to jump into things you accomplished near the end of a job, or at the beginning of another.

> obfuscating the dates

I don't put dates on at all. I never have, even when I was 20.

For most software positions, I’d omit the dates for school, and just note the institution and the degree you obtained. Unless it’s your first job or you’re still working on your degree. You can use dates as filler, but after 1 or 2 positions, in my experience (as an interviewer and interviewee) it tends to be better to sacrifice such details so you can elaborate more on work experience and projects, whilst keeping the resumé a single page. Or put the year on the same line as the school and degree, if you care.

If its present at all I remove the dates

Only APAC companies have asked though, haven’t really bothered with European companies

If you have a CS degree it doesn’t matter what the gap is there to where your years of job experience begins, assuming degree is before experience starts