What is the primary focus of bottom-up programming?

The primary focus of bottom-up programming is to start with detailed implementation and progressively build up to more complex systems. This approach emphasizes the development of individual components or modules first, ensuring that each piece is thoroughly tested and functional before integrating them into larger systems. This method allows developers to ensure that the foundational elements of the software are reliable, which can lead to a more robust overall system. By focusing on smaller components, the bottom-up approach can also facilitate easier debugging and testing since each part is independently verified.

In contrast, approaches such as creating high-level design specifications or debugging completed applications would not be considered bottom-up programming, as they focus on broader perspectives or completed systems rather than incremental development of components. Similarly, while utilizing pre-built libraries can aid software development efficiency, it doesn't align directly with the core principles of bottom-up programming, which centers on building from the ground up rather than relying on established elements.