When you have a niche problem, you can usually reduce it in scope to such level, that you can make significantly better solution than trying to adapt some exist

When you have a niche problem, you can usually reduce it in scope to such level, that you can make significantly better solution than trying to adapt some existing technology. It's not going to be universal, but for your niche problem, it can be much more suited. Back in 2010, I started an open source project for identifying audio files based on fingerprints. I specifically designed everything, so that in the end I need to do super fast i32->i32 lookups on scale. There were many inverted indexes, but they are usually for text search, which has a lot of overhead I don't need. I ended up writing a completely custom solution, and it allowed me to scale to millions and millions of fingerprints on such small servers that it was unimaginable to anyone who ever ran audio fingerprinting system before.