My boy Stammy wrote a really nice, in-depth blog post on how he and his team at Twitter designed the new Twitter Video feature. Absolutely a must-read:
It irks me when designers talk about making specs and handing them over to engineering. The process of “making specs“ implies that there is no conversation with your engineering counterparts when developing. While I have a technical background, I‘m nowhere near the caliber of the engineers at Twitter, so I use this as an opportunity work closely with them to learn more about our iOS and Android codebases, how things are built and determine what‘s feasible.
The smaller the gap between design and the final product the more likely you are to having a product would exactly as you intended it to.