Print on Demand Project Setup - General Questions

First off: I also asked this question on pm.stackexchange.com, but was not really sure if it belongs there. I know it is rather technical and rather basic. If you know a place this would fit in better let me know :-)

I am setting up a Print-On-Demand shop project and just want to ask if my way of handling all the transactions is okay, what would you improve, what would you do different.

Techstack:

• Hosting: Netlify
• Frontend: Gatsby + React
• Customizing Print in the Client: Paper.js
• Checkout: Snipcart
• Printing: Printful API
• Backend/OrderLogistics/Database: Express.js + MongoDB + Netlify Lambda Functions

So the general process is:

• User visits website and edits a design to his liking. The editing options are rather limited, the custom design in displayed via Paper.js
• User clicks "Checkout Now"-Button
• Clientside generates SVG from the Paper.js canvas and the svg + all customization parameters are sent to backend
• Backend stores everything in DB with a unique id
• Unique id is sent back to client
• Snipcart client process is started
• User enters shipping + payment data and confirms purchase
• Payment is processed by Snipcart, unique id + shipping info is sent to Snipcart via API
• Snipcart calls backend webhook when the payment is completed transmitting unique it + shipping info
• Backend looks up design in database based on unique id and builds product in Printful API
• Printful creates order
• I manually doublecheck snipcart backend + printful order, look if everything is as expected and if so confirm the order
• Product is shipped by Printful

I know it is hard to say much about the process without seeing the actual implementation, but just from the basic steps is there anything I should do completely different?

Thank you in advance :-)