Hey Liam, thanks for getting back to me that quickly.
Shopify being an SaaS, there is very little I can do to tweak things. The integration works through the “Algolia Search” app on the Shopify App Store, and there are no parameters to tune for anything regarding indexing speed. On the other hand this means that there should be virtually no environment-specific speed impediments like your other customer experienced.
Shopify does have an API call limit with 2 calls / second though. But 2000 products / hour still only equals ~ 0,56 calls / second. So even if the app uses just one API key internally, there is still capacity left over.
So yeah… still wondering.
(I am actually not quite sure how those app connections work, and if they could use more than one API key. That would be neat!)