Product work gets difficult when the team treats launch as the finish line. In reality, the first release only proves that the system can exist. The next question is whether it can evolve.
Build for change
Architecture should make it easy to move parts of the system without rewriting everything. Clear boundaries and simple contracts are usually more useful than abstract flexibility.
Keep the product legible
When the product, operations, and business stakeholders can all understand the system, decisions get faster and delivery becomes less fragile.
Engineering quality is a business asset
Testing, observability, and documentation reduce the cost of change. That is why product engineering has to be treated as an operating capability, not just a delivery function.