ISO 9001:2015 8.3.4: Design and development controls
The organization controls its design and development process so that: the results sought are defined; reviews are held to judge whether the results can satisfy requirements; verification is done to confirm the outputs satisfy the input requirements; validation is done to confirm the products and services that result are fit for their specified application or intended use; the problems that reviews, verification and validation reveal are acted on; and documented information on all of this is retained.
This control maps to 26 controls across 12 other frameworks. If you already hold one of them, the evidence you collected for it is the starting point here rather than new work.