The disclosed technology teaches rejecting, during validation, a sequence of components intended for interacting with a user. Included are providing a sequence setup GUI supporting construction of an executable sequence by connecting at least five components in a directed graph, and tracing multiple paths through the directed graph, including from at least one conditional branch at a first up-chain component, in which down-chain components accept as input and depend on output from at least one up-chain component, referred to as input chain dependencies. Also included are locating at least one error in use of a particular down-chain component when invoked following one of the multiple paths, where the error results from failure to satisfy any of the input chain dependencies of the particular down-chain component, and reporting the error during validation to a user of the GUI, before passing the sequence of components from validation to use in production.