Hi Cardano developers!
I would like to announce that I’m developing a new indexer framework for Cardano called Mafoc (Maps and folds over Cardano). It’s in the same area as cardano-db-sync and Kupo.
The focus is on writing a Haskell framework that is simple to use for implementing new custom indexers. See the readme for more information. It’s WIP but you can already run it from the cli. It will also likely evolve quite quickly in the coming months.
Challenge me to implement an indexer you need (by creating an issue on github for example or right here in the forum). The idea is to make implementing custom efficient indexers conveniently, your input helps me see angles I haven’t considered.
Join me in developing this if you’d like. 
Go to the readme to learn more or straight to the code.