Where do designs live?
Figma. You review real, clickable designs at a share link and leave comments directly on them. A free Figma account is the one login we do recommend — commenting needs it.
Where does code live?
GitHub, in a private repository. Who owns it — and when it transfers to you — is covered in Who owns the work.
What do we build on?
The platform that fits the project — WordPress for most sites, custom stacks where the product demands it. The choice is part of scoping, made in the open, with the trade-offs explained. [CONFIRM: platform list to publish]