A company is moving forward with a new product. Product scope has been determined, teams have formed, and backlogs have been created. Developers are…

The scenario describes the phase where developers are actively writing, building, and unit testing the software. The description of teams working on REST services, mobile apps, and web applications is a clear depiction of the software being constructed according to the specifications laid out in the design phase. The fact that scope has been determined and backlogs created indicates that the requirements and design phases are largely complete, and the project has moved into the hands-on coding stage, which is the core of the implementation phase.

A. Deployment: This phase involves releasing the finished software to the production environment for users, which is not happening in the scenario.

B. Design: This phase focuses on creating the system architecture and component specifications, which occurs before active coding begins.

D. Requirements: This phase involves gathering and defining what the system must do; the scenario states this has already been completed ("Product scope has been determined").

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1. Sommerville, I. (2016). Software Engineering (10th ed.). Pearson.

In Chapter 2, "Software Processes," the implementation phase (referred to as "Software development") is defined as the process of translating a system specification into an executable system. The activities described in the question—writing code for different application components—directly align with this definition. (See Section 2.1.2, "Software specification, development and validation").

2. Microsoft. (2019). Microsoft Security Development Lifecycle (SDL) – The Practices.

The official Microsoft SDL documentation outlines the "Implementation Phase." This phase is characterized by writing code according to the design specifications and security requirements established in earlier phases. The scenario's description of developers "actively writing code" is the central activity of this phase. (See "SDL Practice #9: Use Only Approved Tools" and "SDL Practice #10: Deprecate Unsafe Functions," which are activities performed during implementation).

3. Bourque, P., & Fairley, R. E. (Eds.). (2014). Guide to the Software Engineering Body of Knowledge (SWEBOK), Version 3.0, IEEE Computer Society.

Chapter 2, "Software Design," and Chapter 3, "Software Construction," differentiate these phases. Software Construction is defined as "the detailed creation of working, meaningful software through a combination of coding, verification, unit testing, integration testing, and debugging." The scenario clearly describes the activities of this phase. (See Chapter 3, Section 1.1, "Definition of Software Construction").