If you happen to be in the unfriendly situation of not getting a chance to mess up any real product development, you may at least follow Per Lundholm’s advice to Write Legacy Code and Secure Your Job. Per provides some excellent tips on how to approach a legacy system. Like by documenting the architecture in just The Right Way:
Use a tool like Word and document the architecture. Yeah, really, just be sure to write at least 100 pages. Perhaps you can find some examples on the internet.
So, it’s hard work. But it pays off. Writing legacy code will not just secure your job, but also make you look better. And it surely helps to make the world more fragile. One line of code at a time.