Your question is missing a couple key inputs. Q: Is your SaaS app targeting enterprise use cases, where the customer will want to enable SSO and centralized pr

Your question is missing a couple key inputs. Q: Is your SaaS app targeting enterprise use cases, where the customer will want to enable SSO and centralized provisioning? Keybase is a reasonable choice in this case because of the SAML and SCIM support. Q: What is your expected revenue per user? Auth0 solves many problems out of the box, but is priced on MAU which can be prohibitive if your revenue per user is low, but deals with lots of complicated issues if not and lets you focus on building your app. I'm the founder of Hellō[0], and if you are targeting consumers or individual professionals and want to give them choice, check it out. As some background, I cofounded the OpenID Foundation, drove creation of OAuth 2.0 and what became JWT, and gave a popular Identity 2.0[1] talk years ago. [0] https://hello.coop https://hello.coop & https://hello.dev https://hello.dev [1] https://www.youtube.com/watch?v=RrpajcAgR1E https://www.youtube.com/watch?v=RrpajcAgR1E