I could care less about amazon or twillio. There literally just aren't easily accessible other buttons / SMS tools if you go look. Nothing about this is pandering to them, I just think it's a bit reductive to say this guy made this post as a promo.

Alternate reality version of the post:

Here's my kubernetes SIP/XMPP/WebRTC orchestration to do SMS and an arduino button I designed with STL files so you can 3D print it yourself. Everything is open source to toilet train your kid! I definitely used my time appropriately!

EDIT: After re-review I realize this man could just not have a child at all. It could definitely be contrived and potty training probably doesn't need Amazon's weird button that orders more soap. I guess all I'm saying is that I could see myself trying out the same thing and the solution doesn't feel that contrived to me.