Abstract: The invention relates to a process for the production of synthesis gas comprising (a) providing a gaseous hydrocarbon stream; (b) subjecting a first part of the gaseous hydrocarbon stream to an endothermic reaction thereby producing a first gaseous reaction product containing hydrogen; (c) subjecting a second part of the gaseous hydrocarbon stream to an exothermic reaction thereby producing a second gaseous reaction product containing hydrogen; (d) transferring thermal energy from said exothermic reaction to said endothermic reaction; and (e) combining the first gaseous reaction product and the second gaseous reaction product produced in steps (b) and (c), thereby forming a gaseous reaction products mixture, and to a reactor that can be used for such a process.