Discussions

I have been experimenting with Shopify Functions lately to build a smarter dynamic bundle system for one of our clients, and I figured I’d share some insights (and a couple of roadblocks). The idea was simple: use Rebuy’s API to suggest complementary products dynamically kind of like “complete the look,” but based on real-time cart behavior rather than static logic.

In theory, it sounded smooth. In practice? Not so much.

We ran into a snag when trying to sync inventory data between Rebuy recommendations and Shopify’s native bundles. The Rebuy API returned great product matches, but Shopify’s Functions wouldn’t trigger updates fast enough when users added or removed items. Ended up with ghost SKUs in a few test orders not fun.

After a few late nights (and more coffee than I’d like to admit), we worked around it by caching the API responses and revalidating every 60 seconds. That kept things quick and clean enough for production. The result: bundles now update instantly when users tweak quantities, and conversion rates nudged up by about 12%.

If anyone’s going down a similar rabbit hole, I’d recommend testing API latency and caching early. Also, if you’re balancing multiple projects like I was while finishing a freelance course on the side don’t be afraid to ask for a bit of help with assignments in Canada or wherever you’re based. Keeps your sanity intact while you’re deep in debug mode.

Anyway, curious how are others handling dynamic logic inside Shopify Functions? Are you leaning more on Rebuy, or rolling your own middleware?

Would love to hear what’s working (or breaking) for you all.