Audience member (a former AOP fan) asks why AOP failed. Krzywda: at the Rails-framework level AOP is alive — DHH promoted Rails callbacks as AOP in 2004 — and in Java AOP is very successful inside Spring. Event-driven DDD effectively simulates AOP: events are 'after' advice, and 'before' advice is rarely needed in practice, so the AOP label faded while the underlying idea survived.