TL;DR: Matt Wayne (the interviewee) talks about a basic problem that agile was supposed to solve: creating software that actually satisfies business requirements. 
For him, Cucumber and BDD solves this problem.<p>But for all other bugs and code defects that happen during software development, mutation analysis works great at increasing the quality of unit tests: <a href="https:&#x2F;&#x2F;en.m.wikipedia.org&#x2F;wiki&#x2F;Mutation_testing" rel="nofollow">https:&#x2F;&#x2F;en.m.wikipedia.org&#x2F;wiki&#x2F;Mutation_testing</a>