If Shopify doesn’t have the feature you want, you can always build it using a custom app. Building a custom app is usually fairly straightforward for a developer who is familiar the Shopify API, but it really depends on what your’re trying to achieve. Naturally, advanced functionality will be more difficult to build than something more straightforward. Shopify apps can be built using a wide variety of programming languages and frameworks, so there is no one set way of developing a Shopify app.