What is the key activity during the 'Development' phase of the software development lifecycle?

The key activity during the 'Development' phase of the software development lifecycle is writing the actual code. This phase involves translating the requirements gathered in the previous stage into working software. Developers take the specifications and turn them into a functional program by writing source code.

This process includes selecting suitable programming languages and development tools, as well as implementing algorithms and data structures that align with the requirements. It's a crucial step within the software development lifecycle, as this is where the ideas and designs begin to take a tangible form that can be tested and eventually deployed.

The other activities, such as gathering requirements, monitoring user feedback, and preparing deployment documents, occur in different phases of the software lifecycle, such as planning or post-development, but they are not the primary focus during the Development phase itself.