Authentication methods
Now that we have updated our database to support the ASP.NET Core Identity authentication workflow and patterns, we should spend some valuable time choosing which authentication method to adopt; more precisely, since we've already implemented the .NET Core IdentityServer, to properly understand whether the default authentication method that it provides for SPAs—JWTs—is safe enough to use or whether we should change it to a more secure mechanism.
As we most certainly know, the HTTP protocol is stateless, meaning that whatever we do during a request/response cycle will be lost before the subsequent request, including the authentication result. The only way we have to overcome this is to store that result somewhere, along with all its relevant data, such as user ID, login date/time, and last request time.
Sessions
Since a few years ago, the most common and traditional method to do this was to store that data on the server using either...