Ask a recruiter how they read a resume and they will describe a careful process. Watch one and you will see something else: a fast scan down the left edge of the page, a pause, and a decision.
The pause is the interesting part.
The three things, in order
Job titles and dates. Are you roughly the right shape for this role, and have you been doing it recently? This takes about two seconds and it is mostly pattern matching. A title that does not exist anywhere else, "Growth Ninja", costs you here, because there is no pattern to match.
The first bullet under the most recent job. This is where the pause happens. It is the only line most recruiters read properly, and it is the line most people waste. If it starts with "Responsible for", the pattern says duty, the pattern says every other resume, and the scan resumes.
Anything that looks like a number. Percentages, currency, team sizes, timeframes. The eye finds digits in a wall of text automatically, which is why a resume with numbers in it reads as more concrete before a single word has been processed.
What this means for the page
Your first bullet under your current role is the most valuable line in the document, and it should be the strongest thing you have ever done, stated as an outcome.
Not this:
Responsible for the email marketing programme across all customer segments.
This:
Rebuilt lifecycle email across six segments, cutting ninety day churn by a third.
Same job. Same person. The second one survives the scan.
The part nobody tells you
Most people rewrite the summary at the top when they are getting no replies. The summary is the least read part of the page. It is a paragraph of adjectives sitting between the recruiter and the thing they are actually looking for.
If you are going to spend an hour on your resume this week, spend it on four bullets: the first one under each of your two most recent roles, and one more under each. That is where the decision is made.