What problem does the paper address, and for whom does it matter?
What must be true about the environment, workload or model for the approach to work?
How does it work, in your own words?
What is new compared with prior work? What is engineering rather than novelty?
Which experiment or argument supports each main claim?
What is it compared against, and are the comparisons fair?
Which components were removed or varied, and what changed?
What does the paper not show? Where might it fail?
What would you need to know to reproduce or reimplement it?
Open questions, experiments you would run, related papers to read next.