Remember, as a designer, you’re responsible for the way the application is supposed to work, therefore, the more involved you are in the development stage, the better it is for the end product. Speed, size, algorithm design, all of these and many other aspects of development are on your shoulders, as much as on those of the developers; these features will impact the user’s impression. Don’t be lazy and attend technical brainstorming sessions, you will be able to help.