Finding the right balance between combining and separating classes and methods is crucial for managing software complexity. There's a "sweet spot" where further separation no longer reduces complexity but actually increases it. The goal is to identify this point to optimize your code's structure.

Here are some key considerations to help you reach that sweet spot:

Combine when information is shared: If different parts of your code heavily rely on and manipulate the same data, consider bringing them together. For example, if you're reading and parsing an HTTP request, keeping these operations together ensures consistent handling of data formats and reduces the risk of information inconsistencies or "leaks" between separate sections.

Combine to simplify interfaces: Consolidating related methods into a single class or module can lead to fewer and simpler interfaces. This reduces the cognitive load on developers using your code, as there are fewer distinct entry points to understand and manage. It also allows for more automation within the combined unit, streamlining development.

Combine to eliminate duplication: Whenever combining code helps eliminate duplication without introducing new complexity or increasing cognitive load, it's a beneficial move. Duplication often leads to inconsistencies and makes maintenance more difficult, so strive to remove it efficiently.

Separate general-purpose from special-purpose code: Recognize that software typically has lower-level, general-purpose components and higher-level, special-purpose components. Avoid mixing these. General-purpose code should be reusable and independent of specific application logic, while special-purpose code addresses particular needs. Keeping them separate promotes modularity and reusability.