We did a lot of customisation using checkout.liquid e.g
Adding a new Delivery Method using JQuery
As you can see above that Ship, Pickup and remaining 2 options are added using custom login in checkout.liquid
When customer click on specific delivery option hide some delivery address fields see
When customer select the specific State show them extra button on the checkout
When customer click on that new link/button show them the popup where there were typing the ZipCode and then we post details to our server to the nearest locations using google API. Custom select the address from the list and that become the delivery address.
Please suggest what can be achieved using checkout extensions ? Any tutorial or document ref would be helpful.
Thank you