In modern software development, various testing approaches are used to ensure applications remain reliable as new features are added. Many small, cheap “unit tests” are used for sanity checks, but don’t offer complete assurance on reliability.
As cloud services move from being startups to enterprise applications, they inevitably must support more and more bespoke use-cases unique to their increasingly upmarket clientele. Given how mission-critical enterprise applications are for large customers, reliability is important. Losing ground on either enterprise functionality or reliability inevitably risks disruption by new startups.