Aquamarine is the multi-process composition medium based on pi-calculus, designed for distributed applications/backends, both in private deployments and open networks. Aquamarine scripts define the topology of the execution (when and where to move control flow) and data dependency graph (what results and what arguments to pass where), essentially describing the composition of (micro)services, e.g. using one service's output as another service's input. The language primitives are based on pi-calculus operations describing certain topological effects and secured by cryptographic signatures of involved peers. The Aquamarine approach allows building distributed systems of any complexity, effectively expressing network behavior.