Shopify Developer Needed for Site Optimisation

We are looking for an experienced Shopify Developer to fix some issues on our existing Shopify store.

Currently, we are facing two major problems:

The website is loading slowly, which is affecting the overall user experience.
There is an issue on the checkout/payment page, and customers are experiencing problems while proceeding with the checkout process.
Project Requirements

The selected Shopify expert will be responsible for:

Identifying the reason behind the slow website loading speed
Optimizing the Shopify store for better performance
Checking themes, apps, scripts, images, and other elements affecting website speed
Fixing the checkout page issue
Investigating any errors related to the payment/checkout process
Ensuring customers can smoothly proceed through checkout
Testing the website and checkout process on both mobile and desktop
Removing or fixing unnecessary code, scripts, or app conflicts if required
Improving the overall performance and user experience of the Shopify store