I urge everyone to bookmark that blog; it is always a fascinating tour of the weirder and wonderfuller places on our planet. And let me leave you with this simply jaw-dropping video of undulatus asperatus in action.
(A sunscreen with a physical block like titanium dioxide or zinc oxide can be applied last, after a serum or moisturizer.) Apply a serum next and, finally, moisturizer if you need it. Polis also recommends serums or sunscreens with moisturizers built in because they save time.
After that it depends. If your sunscreen contains only Titanium Dioxide and/or Zinc Oxide, you can apply it after moisturizer. If, instead, it contains other sunscreen agents, such as avobenzone or mexoryl for instance, apply it a couple of minutes after the fairness cream and then slather on moisturizer.