Why OAuth2 for SPAs Is Harder Than the Tutorials Make It Look

You’ve probably been there: building a Single Page Application (SPA), needing authentication, and thinking “OAuth2 is a standard, this should be straightforward.” Then you dive into the implementation and realize the tutorials all conveniently skip the hard parts. Three weeks later, you’re debugging redirect loops at midnight, questioning your life choices, and wondering why something that’s supposed to be “standard” feels so fragile. After years of working on identity solutions and helping teams implement OAuth2 in production SPAs, I can tell you that this frustration is universal.