Well. Step 1 is monitoring legal requirements around the world. In all the 50 US states, 200 countries, and whatever other kind of jurisdiction feels important.

You have to age gate social media for 16+ in Australia. Some content is criminal in some countries. Some content is 18+ in some countries but not in others. Some countries require such content to be age gated, others do not.

What kind of age verification is acceptable also varies…

You need to constantly have your eye on new laws, legal precedents, or decision by regulators and adapt.

And that doesn’t even begin to address the technological problems.