I've had great feedback from users, and there's quite a high conversion ratio (about 15%) from the free trial. However, I'm having trouble growing. I've tried reducing the price, but that's not the root of the issue - I don't have enough people trying it and even looking at the price.
I posted it on Reddit and Producthunt early on, but I was stupid and did it far too early before it was mature - it didn't even have a free trial. I've also tried reddit ads, to no avail - it was all bots.
I also wrote and shared a technical blog post, but that wasn't particularly successful and honestly there isn't that much to talk about technically. I've made sensible choices of data structures (mostly bloom filters and perfect hash functions), used WASM, and thought about performance throughout, but there's nothing quite worth a blog post.