1. A computer-implemented method comprising: receiving a plurality of user queries; accessing at least first and second experiments associated with a plurality of parameters, with the first experiment being different from the second experiment, with the first experiment for adjusting a first value of a first parameter associated with processing one of the received user queries, with the second experiment for adjusting a second value of a second parameter associated with processing the one of the received user queries, and with the first parameter being different from the second parameter; grouping at least the first and second experiments into a domain selected from two or more domains, wherein: the domain comprises at least a first layer and a second layer, the first layer comprising at least the first experiment and the second layer comprising at least the second experiment; the domain further comprises a launch layer for generating a first default value for the first parameter of the first experiment and a second default value for the second parameter of the second experiment; and at most one experiment from the first layer and at most one experiment from the second layer is allowed to be performed on the one of the received user queries; and selecting, from the first layer, the first experiment; selecting, from the second layer, the second experiment; and performing the first and the second experiments on the one of the received user queries.