I got a tour of the 'Wholesale' and Quick Order Entry that was part of Shopify Plus, couldn't believe anyone would use it. Eventually stumbled on SparkLayer and have found it great so far. Not perfect, as it's more of a layer on top of the store... But it means maintaining only one store - https://sparklayer.io/. Source: about 2 years ago

This! Medusa or 🤩Commerce.jj are the best options I have seen to date. Also depends on complexity of use case. I would run one of the known solutions so you can focus on your business. Source: about 1 year ago

Commercejs: https://commercejs.com The problem here is that we can manage multiple merchants, however, each merchant has its API private/public key combination, payment integration, customer list, etc, So we don't have centralized customer lists for us but only for each merchant we create. Otherwise, it would be cool. Not sure about payment integration as a marketplace from Stipe/Adyen as it seems only to... Source: over 1 year ago

With Commerce.js, you’ll have a modern, API-driven headless commerce infrastructure for developers. Founded in 2016, it focuses on being able to help eCommerce businesses, from startup to enterprise-sized, create great digital commerce experiences. - Source: dev.to / over 1 year ago

If you really just want to sell a simple basic product and want to just add that ability to a next js site use snipcart https://snipcart.com even some lite e-commerce use https://commercejs.com. Source: over 1 year ago

Commerce.js, founded by Andrew Underwood and Devan Koshal in 2016, is an API-driven infrastructure for developers. It boasts helping any business, from startup to enterprise, build purchasing experiences across channels, including VR commerce. - Source: dev.to / almost 2 years ago