Understanding the problem in production

The challenge in complex systems is the fact that detecting problems becomes exponentially more complicated. As multiple layers and modules are added and interact with each other, bugs become potentially more subtle and more complex.

As we saw before, microservice architectures can be especially difficult to debug. The interaction between different microservices can produce complex interactions that can produce subtle problems in the integration of its different parts. This integration can be difficult to test in integration tests, or perhaps the source of the problem is in a blind spot of the integration tests.

But monoliths can also have problems as their parts grow more complex. Difficult bugs may be produced due to the interaction of specific production data that interacts in an unexpected way. A big advantage of monolithic systems is that the tests will cover the whole system, making it easier to replicate with unit or...