We may resolve to use The Graph at some point.
Previously we were using direct contract reads: https://ethereum.stackexchange.com/questions/151572/the-simplest-way-to-return-a-list-of-items-gas-limits-on-long-lists-when-using
The deployment happens from the personal repo: https://github.com/basexhq/back-end
(matter of keeping the monthly subscriptions cost low, that is likely to be changed at some point)