What I would be interested to know is: What open source alternatives exist which tackle this problem and how battle-tested are they (esp. given than SSO differs between org to org)? With a product I built, I just paid the Okta tax and had Okta handle all the complexity of integrating with external systems while providing a single interface for me to interact with (which on the surface is the same thing WorkOS promises), but if I'm inclined to build this out myself, what are the alternatives?
I see a lot of devs, especially on HN, complain about http://sso.tax, but until you build a product for exterprise, you'll really not understand the time and effort this takes (and all of this takes away time and effort that could be spent building your product)