[heliodor]

Not implementing it yourself does not imply that you should use auth-as-a-service. There are plenty of auth libraries out there for your programming language of choice. Take a look at their source code and see how much stuff is in there to get a sense of why you should not implement your own.

I use django-allauth: https://github.com/pennersr/django-allauth

[jaeming]

Oh yeah, for sure, there are a really good libs. Someone mentioned passport. I've personally used Devise/warden in Rails. Though we had to monkey patch/extend it so much that 6 years later it was almost a different beast entirely.

But I'd still argue it's worth knowing what those libs are doing for you and you can only really appreciate it once you've rolled your own. I've done so on many a personal project where the risk was low. But yeah honestly, if I was rolling a large-scale enterprise app today, I'd probably utilize AWS Cognito. But this is also not for the faint of heart IMO.

[Fire-Dragon-DoL]

The authentication portion of devise is actually really small!