All software systems are legacy systems

Author: Dave Anderson (Daveanderson)

Even at the forefront of the system, the latest technology was developed, but it would be a legacy system for the next person to take over. This situation must be addressed. Today, software quickly becomes obsolete, which has become a natural attribute of software. If the system survives as a product, even for a few months, it must be admitted that the developer responsible for the maintenance work is sure to defect the software, which is unavoidable, which leads to several issues.

Clarity (clarity): The roles of individual components and classes must be clear. Testability (testability): The system is easy to verify. Correctness (correctness): The result is consistent with the design or expectation. Avoid the kind of repair that is fast but means poor (quick and nasty). Traceable (traceability): Assuming Ernie (Ernie) is responsible for fixing the emergency defect, but he has never seen the code before, he can jump into the product immediately diagnose the fault and resolve it immediately. It will take 8 weeks to transfer the time.

Assuming different teams open the codebase, it's easy to see what's going on, and that's the foundation of a good architecture. There is no need to over-simplify or prepare exhaustive documentation for the architecture; Good design describes itself in many ways. The system behavior in the production environment also illustrates its design, for example, a structure with a very ugly dependency, whose behavior often looks like a caged beast and is restricted everywhere. Think about the developers who are going to debug the bug (usually the more junior ones).

In the software world, "legacy systems" (Legacy) are not good words, but in practice, all software systems should not exclude this tag. It's not a bad thing, because it may also indicate that your system is proven, predictable, and commercially valuable. Any software system that has never been called a "legacy system" may have been abandoned before it was released, which is not a sign that the software architect has succeeded.