If your e-store starts to have considerable sales volume then it makes sense to implement service that packs and ships products on your behalf. Something similar like Fulfilment By Amazon.
There is Swedish Company Ongoing Warehouse Management Systems that provides software for logistics companies. This software has API which allows e-stores to send order details for order fulfillment.
One of the automatic fulfillment providers with this software is Boomerang Distribution in Estonia.
I have built integration between Bold Tuesday Shopify e-commerce store and Boomerang fulfilment service. While usually I build my applications in Laravel framework and in PHP then in this case the Ongoing warehouse API integration had some issues with SOAP structure validation and I decided to build this integration with NodeJS instead.