3 Comments
User's avatar
Quentin's avatar

Great insight ! what a coincidence, I just wrote about it today too, you might take a look at it : https://quentin209.substack.com/p/postgres-vs-elasticsearch-for-hybrid?r=7pgxx7

One caveat I had with this method is that ts_rank and ts_rank_cd methods are not as sharp as BM25 can be within elastic search, and that can be a little confusing first hand

Think AI's avatar

Great breakdown. Search at Instacart is not just keyword matching; it is about intent, ranking, inventory, and real-time product availability. Curious question: what is harder at this scale, showing the most relevant product or keeping results accurate when inventory changes store by store?

Ex-Consultant in Tech's avatar

The deeper lesson is that AI search only creates business value when it is tied to operational truth. Grocery is messy: products go out of stock, stores vary by location, names are inconsistent, and customer language rarely matches catalog taxonomy. A standalone “smart search” layer is not enough if it is disconnected from fresh inventory and business rules.