Why most resume bullets fail
A weak bullet almost always fails in the same way: it describes a responsibility instead of a result. "Responsible for the payments API" tells a reader what your job title already told them. "Cut p99 latency on the payments API from 900ms to 210ms" tells them what happened because you were there, and those are different documents.
The fix is a number, which is exactly where people get into trouble. Faced with a bullet that has no measurable outcome, the tempting move is to estimate one - and an estimate written into a resume becomes a claim you have to defend, under pressure, to the person who will ask how you measured it.

