What you say is absolutely true, and I agree. But I also subscribe to the URLs-are-user-interface school of thought and think that implementing redirects to cha

What you say is absolutely true, and I agree. But I also subscribe to the URLs-are-user-interface school of thought and think that implementing redirects to change your UI requires careful thought. I'll admit that sometimes it is unavoidable as applications change over time. Maintaining state in the path, query parameters, or fragment are all techniques that can work, but each comes with disadvantages. I wonder if anyone has been mad enough to maintain state in subdomains: https://accnumber18573.color-yellow.example.com/ https://accnumber18573.color-yellow.example.com/