Auth0

Never Compromise on Identity. Provide a universal authentication & authorization platform for web, mobile and legacy applications. Developers can connect any application written in any language or stack, and define the external identity providers, as well as integrations, that they want to use. Provides greater control, superior security, and ease of use. Give customers, partners and employees the freedom of Single Sign-On while keeping the control and enhanced security you need.

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Why I love it

Auth0, if used correctly, it can offer you 10-20% of more revenue. I am actually wondering about their identity positioning when it can be insanely useful in retention optimisation as well.
Aggelos M.
Product-led expect