How to build a system development for digital sales?

Question

Work organization

Hello. We need advice, we need to build a system for the digital sale of goods.
Due to the specifics, the idea is that all information for sales is stored on a separate server. This system is also a small CRM to keep track of deliveries, statuses, etc. Supplier systems are connected to this server via API. Such a gasket is needed for security, and simplification of management - managing everything in one place. This, of course, samopis.
Next - 2 sites - a store (in the future, connecting third-party stores). The API sucks information from CRM.
Here I am very unsure how to proceed. On the one hand, I was almost sure that I wanted 2 of these stores on Opencart, because. almost all the necessary functionality is there, sales analytics, etc., a lot of plugins and information. Made a design - and drove to sell. On the other hand, I doubted how good it would be to use a free CMS, given that it would require quite a bit of customization in terms of development, and the security is questionable. Well, you need to have tools for marketing, analytics, etc. What to do? :)
And how best to organize the development, that it cost space money? Looking for a team to outsource, or try to look for a developer in the state, and outsource what he will not do himself (design, marketing, etc.)? Your own programmer in the team seems more promising, given that improvements will definitely be required, but I'm afraid that over time the amount of work will disappear, and it's not clear what to do with him then.

Answer 1

You can go to the university and find hungry students there ready to earn extra money. The only thing is that you need to demand that after the final development they provide all the sorts and proof that the code was built on these sorts. Well, some minimal documentation. This is for a start.
And then - how will it go.

Answer 2

You need to start with the preparation of project documentation. While everything is very amorphous.
For what you described exactly one of the commercial CMS is suitable. But what is left behind the scenes can ruin the life of both you and the team.

Answer 3

The best option to implement a new CPM! For example, you can contact the platform https://perfectum.ua/ , where the guys will help you.