Which phase of the software development life cycle includes writing application code?

The phase of the software development life cycle that includes writing application code is known as Developing. During this phase, developers actively create the software by programming and compiling the application code according to the design specifications established in earlier phases. This is the stage where the theoretical aspects of the design are transformed into a working application.

In the context of the software development life cycle, Developing is focused on the actual coding of the application. It encompasses all activities related to writing, testing, and debugging the code, ensuring that the application functions as intended. This phase is crucial as it combines technical skills with the foundational design elements that were defined prior.

While the other phases, such as Defining, Designing, and Implementing, contribute to the overall development process, they do not involve the actual writing of code. Defining involves understanding and gathering requirements, designing focuses on architectural and user interface planning, and Implementing typically refers to the deployment of the software rather than its development. Hence, Developing accurately represents the phase dedicated to writing the application code.