Microsoft's Raymond posted this little story about the security of their Benefits application back when Microsoft's email address had exclamation points.
Two of the companies I worked for had some security loopholes as well. One had an application that was used to view license files, compiled as a native app, and the original app was written in Java. Once I figured that out, I extracted the Java app from the native app, reverse engineered the application, and wrote a C# application to do the same thing!
And the other company had their one-time password to decrypt application data files within their own obfuscated Java application. Despite the obfuscator being a world-class app, as I am well versed in Java, once I figured out how the decryption process went, I was able to write an application to generate the one-time passwords for decrypting the data files.
And by now, I have a pretty solid idea how I can go about writing my own VM decompiler, despite there being several available.
In 2017, with the release of Delphi 10.2 Tokyo, Embarcadero introduced a specialized implementation of the Observer pattern into the System.Classes unit. While it has been in the wild for 9 years, it remains a "hidden" architecture for many, primarily because it serves as the invisible engine behind LiveBindings. Other than live bindings, you can also use the Observer pattern as a way to update component settings to the Windows registry, an .ini file, or persist it elsewhere.
System.Classes