I built a crypto screener to help find promising coins. It currently handles over 400, with plans to go much bigger! 
It's got smart filtering – no browser slowdowns – and lets you set up complex screening rules. I'm using F# and TypeScript for the tech.
It's part of a bigger backtesting platform I’m developing, and I'm looking for feedback on how easy it is to use, especially the filtering, and what other criteria would be helpful. Check it out: https://cryptoquant.dev/instruments/screener.