The article does talks about how to inject latency or packet-loss into calls to particular external services. This should help you test many service->dependency

The article does talks about how to inject latency or packet-loss into calls to particular external services. This should help you test many service->dependency failure scenarios around retries, timeouts and circuit-breakers. Injecting specific error codes or exceptions is a bit more complicated but it is possible with other approaches, for example: Chaos toolkit.