In an aspect, the present disclosure provides a method for the oxidative coupling of methane to generate hydrocarbon compounds containing at least two carbon atoms (C2+ compounds). The method can include mixing a first gas stream comprising methane with a second gas stream comprising oxygen to form a third gas stream comprising methane and oxygen and performing an oxidative coupling of methane (OCM) reaction using the third gas stream to produce a product stream comprising one or more C2+ compounds.