1. A system, comprising: a memory that stores computer executable components; and a processor that executes the computer executable components stored in the memory, wherein the computer executable components comprise: a prioritization component that: determines respective failure impact values of application program interface call subgraphs associated with a user interface of a microservices-based application based on a failure impact function employed on an annotated state transition graph, wherein the failure impact function comprises: for respective edges of the state transition graph: a determination of a set of nodes of the annotated state transition graph reachable from an edge, for respective nodes of the set of nodes, a determination of a count of user interface events, able to be triggered from a user interface state represented by a node, that fail to be able to be triggered from other user interface states represented by other nodes along a path from the edge to the node, and a determination of a failure impact value for the edge based on summing of counts for the nodes of the set of nodes; and generates an ordered list of the application program interface call subgraphs, wherein the application program interface call subgraphs are ordered based on the respective failure impact values; and a test execution component that iteratively performs in the order of the ordered list for respective application program interface call subgraphs of a subset of application program interface call subgraphs: based on at least one resiliency test pattern, generation of at least one failure scenario for an application program interface call subgraph of the subset of application program interface call subgraphs; and test of the application program interface call subgraph for the at least one resiliency pattern using the at least one failure scenario.