I've now built from scratch two complex online marketplaces that were both designed to bring efficiencies to two B2B industries. The platforms were global, with complex parameters in the transaction, requiring high quality data & standards... and with tricky, 'non-tech' customer segments on both sides!

I'd be delighted to support you in the initial stages of planning the structure of your marketplace: commercial models, catering for customer psychologies, UX/UI etc