Here are the four things you’d want to discuss with your devs re: implementation and hand off:
1. Is our project plan realistic?
Before you even start designing, ask your team: Can we achieve the client’s required features within the timeline and budget allowed? If not, what are the things that we’d want to hold off on/talk to client about? What are the most important features?
2. Am I missing any key functionality?
During sitemapping and wireframing, developers can help you review starting with the first round. Typically I do ~3 presentable rounds of wireframes and get feedback on each round from the internal team — which includes dev — and then make changes before I present to the client. Ask them what they think of your solutions. Note that it is not the developer’s job to tell you ALL functionality you need — this is your job to figure out as a UX designer! — but they can help you fill in any gaps you may have overlooked. If you’re unsure how something works or what functionality you need, e.g. a certain flow, check out other designs/products that are similar. Use them and see how they work. What is working nicely? What could be better? Use this to inform your solutions.
3. How will you provide design specifications (specs)?
This is the big divide between design and dev. Common scenario: you create pixel perfect polished designs and hand them off to dev. When they’re built, they look totally different and all the sizes and spacing is off. What gives? Well… It’s up to you and your dev team to plan and discuss what they expect to receive from you. Do they need a redline doc? Will your team use Marvel, Zeplin, Figma, InVision or Sketch to share design specs? Ask yourself what you can do to help make their job easier. As designers, we need to understand how devs work (and vice versa!) to make sure handoff is as seamless as possible and everyone is happy with the final outcomes.
4. How will you deliver UI and assets?
In addition to handing off your final designs, you’ll want to give them a UI kit or guidelines to work with. Are you giving them super detailed redlines as mentioned above? Are they willing to open the working file in Sketch/Figma/whatever you’re using and take measurements if they need to? Are they going to use a tool like Zeplin or InVision to inspect your designs? Basic things to provide include text styles and sizes, colors, buttons, navigation, and all visual assets such as iconography, illustrations, photos, and video. You also want to consider states and interactions (e.g. what happens when a user clicks this dropdown? What does hovering over a button look like? What if a user gets to a page with no results?) This is where prototyping comes in handy.