I used to build a lot of Shopify sites and this was a common request. Mostly, it stems from the customer imagining that the complex automated feature they want

I used to build a lot of Shopify sites and this was a common request. Mostly, it stems from the customer imagining that the complex automated feature they want is actually a lot simpler to implement than it is. Folks are used to interacting with $1M+ websites and expect their small business site to have the same look or functionality. It won't. Shopify already gets people closer to big sites than was ever possible before, especially with the judicious use of add-ons from their store. It's very likely that the feature you want can be found there. It is possible to write custom code for Shopify and sometimes that's necessary, but the only time I ever did it successfully was for companies that were already $1M+ businesses. They could afford to invest in customization because they had the sales to back it up.