A method (200) for producing a microfluidic apparatus (100) according to one or more design constraints. The method comprises: providing (210) a first substrate (110) comprising multiple fluid channels (120), wherein the channels have an inlet (123) and an outlet (124); implementing (220) a configuration of connecting channels (150) on at least one second substrate (140) depending on the specified design constraints of the microfluidic apparatus (100); such that by aligning (230) the first substrate with the at least one second substrate, at least some inlets and outlets of the fluid channels of the first substrate are connected to the connecting channels (150) and a microfluidic device (100) complying with the one or more design constraints is obtained.