[gingerlime]

Thanks for the link. We're pretty much using this pyramid approach intuitively, but just as a single data point - one feature test takes around 15% of the execution of our entire test suite (with around 850 tests). This one test is quite comprehensive and touches the core functionality, but nevertheless suffers from all the negative aspects Martin Fowler mentions.

Were we to improve our unit tests to run even faster, as the post suggests, the difference in execution time will become much more pronounced. several orders of magnitude.

I think feature/UI testing is still an interesting space for better tools, but of course the problem is very difficult to solve.