Sam and Ryan discuss new videos on async testing and declarative form validations. They also talk about why it's so hard to create good abstractions in Ember, or more generally the front-end landscape. They discuss constraints versus flexibility, and how the size of a library's problem space affects the likelihood of arriving at a good abstraction.
Topics include:

01:14: Lessons learned from the Async Testing series
06:20: Forms: declarative validations, building blocks & escape hatches
12:56: Why building forms in UI libraries is hard – unconstrained environments
30:45: Philosophical differences, and over- vs. under-abstracting

Links:

EmberMap's premium series on Async Testing
Andrew Clark on Twitter