What should UI/UX design deliver before development?
Design explains how people will use the product and what happens at each step. Useful deliverables let you test the idea and give developers clear decisions to implement.
Map the task before polishing screens
Identify who arrives, what they need to finish, and the information and choices involved. Review new and returning users and different roles.
Agree the content and steps before visual polish. A prototype can expose an unnecessary step or missing information before implementation.
Include the states people will encounter
A screen needs loading, empty and error states. Explain what can be changed and who has permission to do it.
Try Arabic, English and phone layouts early. Shrinking a desktop layout is insufficient when priorities or input methods differ.
Hand over implementable decisions
Deliver reusable components, form and button behavior, and a prototype of important journeys. Agree how design will be reviewed during implementation.
Accessibility belongs in those decisions, including readable text, field labels and keyboard use. The linked W3C introduction explains the general principles.