Secure-Software-Design Exam Question 21

A company is moving forward with a new product. Product scope has been determined, teams have formed, and backlogs have been created. Developers areactively writing code for the new product, with one team concentrating on delivering data via REST services, one Team working on the mobile apps, and a third team writing the web application.
Which phase of the software developmentlifecycle(SDLC) is being described?