There are 3 levels of difficulty: 1) Shopify is probably the easiest to develop if you use the pre-built templates and the applications available in the Shopify Marketplace 2) Headless platform like Commerce Layer, are simple to develop but they require basic programming skills 3) Salesforce Commerce Cloud and Adobe Commerce are the most difficult and intensive platforms to develop and customise as they require high effort by programmers and specific technical knowledge of the platform, if you want to customise them.