Here is the thing: The paradigms of your initial design, or if you're in a better situation, the first refactor, is likely to stay. If performance is what you t

Here is the thing: The paradigms of your initial design, or if you're in a better situation, the first refactor, is likely to stay. If performance is what you think about last, you choose different paradigms (like e.g. polymorphism). From my experience, a winning strategy is to think about things that scale already in the initial design, and what scales in a backend-system is often the amount of data you want to pipe through it. Thus, keeping it data centric (primitive types and arrays for raw data), while using polymorphism and functional interfaces to keep the methodologies clean, is usually a good idea. So, most code that I write tends to have dead simple data types, but combines it with classes (and subclasses) that represent methods (strategies) on how to retrieve, transform, present and store the data. The 'make it work' phase may do this in a simple script, but the actual data model tends to stay the same.