I'm building an app with APIs that need auth, should I use a hosted provider or roll my own?

In most cases, use a hosted auth provider unless you have a strong reason not to.

Go hosted if:

• You want to move fast
• You need common features like:
  • login/signup
  • password reset
  • email verification
  • social login
  • MFA
  • account recovery
• You don’t want to maintain security-sensitive auth code
• You’d rather spend time on your product than auth edge cases

Examples: Auth0, Clerk, Supabase Auth, Firebase Auth, Cognito, WorkOS.

Roll your own if:

• Auth is a core differentiator of your product
• You have strict compliance / regulatory needs that a provider can’t meet
• You need very custom identity flows
• You have the security expertise to do it correctly
• You can afford the long-term maintenance burden

Important reality:

Rolling your own auth is usually much harder than it looks. Common mistakes include:

• weak password storage
• broken session handling
• insecure JWT usage
• bad token revocation
• CSRF/XSS issues
• account enumeration
• password reset vulnerabilities
• MFA bypasses

If you roll your own, you’re signing up for ongoing security work, audits, and incident response.

A practical rule of thumb

• Startup / MVP / small team: hosted provider
• Large org with security team and unusual requirements: maybe custom
• Internal APIs only: maybe simpler auth like OIDC via an IdP, but still usually not truly “from scratch”

Best compromise

Use a provider for identity, and keep your app authorization logic in your backend:

• provider handles login, MFA, password recovery
• your app handles roles, permissions, tenant access, resource-level authorization

That usually gives the best balance of speed and control.

If you want, I can help you choose between Auth0 vs Clerk vs Supabase vs Cognito based on your stack and requirements.