I don't know whether it's just a coincidence that I've been tasked with ASP.NET Identity / Membership during my total career, or it's something in my personality that makes me a suitable candidate for implementing such features. I remember from adding ASP.NET WebForm Membership to old school web projects to recent strugglings with ASP.NET Core Identity.
Fortunately, the core concept has not changed a lot. Both implementations across different versions share similar database tables, even ASPNET_Users table is similar. SignInManager, ApplicationUserManager and similar classes expose similar APIs in the same way. During the years, user claims has played a more profound role and, the only significant change is the emerging of JWT.
To my pleasure, SO questions on the matter have been attractive for me. I'm always glad to try on those type of questions.
Last night, after reading some parts of book code simplicity, I was trying to calculate how many users have been registered or authenticated through the code I've installed on the project or customized for business purposes. In fact, registration frequency is not very high, as most of my works has been used in businesses rather than being online services. I have an applications in my resume with 700K users, although most of these number of users has been imported via database operations. In another project, about 200 users exists in the database. This system is alive for about 8 years. In each business day, about 200 login/logout happens. Totally, 50K login/logout each year. Finally, 400K login/logout so far which looks like a big number. In another project which is installed for several customers, 10 active users exists per customer. I guess 5 logins happen per day while there are 30 customers roughly. Consequently, 39K logins happens per year per total customers. It is expected that this reaches one million in a 25 years period. However, as Refresh Token has been employed in the 3rd project, the number goes even higher.
For more information about the equation of software design read the book or see this entry.