[Shopify] I have indexed / reindexed a product, but it's not appearing in searches

If you know that a product is contained within your index, but it's not appearing in search results, first check if the product was indexed with a algolia_ignore tag. Removing this tag should mean the item is displayed the product in searches.

You can also verify:

If the  products are part of the Online Store channel?

https://www.algolia.com/doc/integration/shopify/sending-and-managing-data/schemas/?client=ruby#products

And that they are Published/Active and not marked hidden or ignored? 

https://www.algolia.com/doc/integration/shopify/sending-and-managing-data/schemas/?client=ruby#skipping-a-product

Also, if they were marked Available using the batch editor tool?

https://www.algolia.com/doc/integration/shopify/troubleshooting/frequent-issues/?client=ruby#products-dont-get-updated-when-marking-them-availableunavailable