Auth0

Auth0 is the “just let someone else handle login” platform — and honestly, that’s the right call. It provides drop-in authentication for web, mobile, and API applications, supporting social logins, passwordless auth, MFA, and enterprise connections like SAML and LDAP. With SDKs for practically every language and framework, you can go from zero to “users can log in” in about fifteen minutes.

Acquired by Okta in 2021, Auth0 continues to operate as a separate product unit focused on developer experience. It handles the OAuth 2.0 and OpenID Connect flows so you don’t have to read those RFCs yourself. Because building your own auth system from scratch is how security incidents are born — and how developers learn the hard way that password hashing is not the same as password encryption.

Why it matters: Auth0 proved that authentication is a solved problem — you just need to stop re-solving it. It let developers focus on their actual product instead of spending weeks perfecting password reset flows and session management.