This is stupid/dangerous advice and I will die on this hill.
> The JWT specification is specifically designed only for very short-live tokens (~5 minute or less). Sessions need to have longer lifespans than that.
Your auth token should be 5 or 10 minutes long, yes. Your session should be encoded in a refresh token, which can be another JWT or completely opaque, whichever you prefer.
> "stateless" authentication simply is not feasible in a secure way. You must have some state to handle tokens securely, and if you must have a data store, it's better to just store all the data. Most of this article and the followup it links to describes the specific issues:
No. Stateless auth is completely feasible in a secure fashion. You need short lived tokens as stated above, and to perform instant logout you need to be able to identify JWTs that were invalidated at the level of your API gateway. You don't need to store every JWT that is valid, only a way to identify the ones you want to invalidate early. If you make bulk invalidations not go onto this store (and just accept that with bulk logout, users will remain logged in for up to 5 minutes, which if you're doing logouts in bulk, this does not matter to begin with), then this typically fits in memory. "if you must have a data store, it's better to just store all the data" is just wrong.
And of course for refreshing the token, you go to your data store and recompute things. But the point is to do this every 5-10 minutes like the author (correctly) identified, not on every API request.
> JWTs which just store a simple session token are inefficient and less flexible than a regular session cookie, and don't gain you any advantage.
But no one does this. People use JWTs as auth tokens which are short lived but contain a bunch of information about the users that you'd get in huge trouble if it could be forged (user ids, resolved geolocation, entitlements, cohorts, etc etc), but that you also don't want to make every service of yours look up against a data store or compute for every single API request. It should be data that normally doesn't change during the duration of the auth token. When it does change, you should have a mechanism to immediately invalidate the previous one (see above) and issue a new one on the API call that made the change. Simple.
> The JWT specification itself is not trusted by security experts. This should preclude all usage of them for anything related to security and authentication. The original spec specifically made it possible to create fake tokens, and is likely to contain other mistakes. This article delves deeper into the problems with the JWT (family) specification.
Yes, all standards are horrible if you look at them long enough. XML is terrible, YAML is terrible, ASN.1 is horrific. I'll take a flawed standard that has been studied and criticized publicly so I have libraries and know where the footguns are vs rolling everything myself and having to find out the footguns on my own.