Cross-Domain Connections
Where this domain touches databases, distributed systems, backends, cloud, delivery, observability and security — and exactly where each of those owns the depth.
The seam is the write-ahead log. Almost every mechanism a source database uses to stay correct decides what a pipeline downstream of it is able to promise.
A pipeline does not choose its guarantees. It inherits them from the weakest hop, and most pipeline bugs are a distributed-systems property arriving where nobody expected it.
The backend produces transactions, events and logs as a side effect of serving users. We are its downstream consumer, and it usually does not know that.
A data platform is assembled almost entirely from four cloud primitives. Knowing which four, and what each actually charges you for, is most of platform engineering.
Transformation code deploys like software. The tables it already wrote do not, and that asymmetry is the whole lesson.
Observability & Performance owns why it is slow. This domain owns whether it is correct, complete and fresh. Different questions, different signals, different toolkits.
A pipeline is a machine for making copies. Every copy inherits the original's obligations and none of the mechanisms that were enforcing them.