BTC is the next obvious step.
The most challenging thing is to find relative off-chain data. It's still in progress.
The feature I'm working on is finding paths between 2 wallets. However, I was forced to remove it because it's not stable enough and consumes too many resources.
I initially tried using Memgraph but faced stability issues and a lack of flow control tools during traversal, making it impossible to load one month’s worth of Ethereum blockchain data. The current solution, however, handles 10 times more data hosted on the same machine.
ClickHouse is an excellent database, provided you don't need to traverse graphs. Graph traversal requires many queries, and frequent disk interactions can significantly degrade performance.
The feature I'm working on is finding paths between 2 wallets. However, I was forced to remove it because it's not stable enough and consumes too many resources.