Whole genome sequencing is now happening at scale. Take a snapshot of each person at a young age, say 20, and then archive it. Later use genome editing to rewrite the genome back to what it was at a younger age?
Large samples of whole genome sequencing has now been done, and as costs come down it should be possible to do extensive deep sequencing across some tissue samples and track people longitudinally, to see which somatic mutations, precisely, are associated with aging profiles. Then you could start by targeting gene editing of mutations in significant pathways.
Gene therapy for congenital disorders in adults is now being done:
https://www.science.org/content/article/first-gene-editing-t...
https://www.axios.com/crispr-gene-editing-patient-ac724626-0...
https://www.aamc.org/news-insights/future-crispr-now
If you think about aging as an acquired genetic disease, and gene therapy as an intervention, it makes sense.