Shopify developer for adding some custom functions to my store

I am looking for a Shopify developer who can add some custom functions to my store. I am open to suggestions for the specific custom functions that need to be added. The timeline for this project is within a month.

Skills and experience required:
- Expertise in Shopify development
- Experience in customizing the checkout process
- Proficiency in advanced product filtering
- Knowledge of customized shipping options
- Ability to work within the given timeline