The context

A marketplace for video game items, with a catalogue of several million listings and steady traffic. Search queried the database on every request, which weighed on the servers at peak hours.

What I did

I pulled search out into a dedicated service. It builds an in-memory index from the database, shares it across several processes and updates it by difference rather than rebuilding it. Queries no longer touch the database. I also work on the back office: sales administration, outgoing payments, internal tools.

In short

Several million listings served from memory, without touching the database.