Expression compilation is incredibly slow right now, even for incredibly small schemas.
We should profiling just expression compilation and see if there is any low hanging fruit that could easily be sped up. One potential place is the type converter, which is a just match case. This is probably very slow when the match is at the bottom of this list. We likely want to use a hash lookup for this.
Additionally, there have been some reports that the scala parser combinator library is fairly poor (both slow and memory inefficient), so it may be worth looking into alternatives. The [https://github.com/lihaoyi/fastparse|fastparse] library might be a good alternative, though it does not appear to be a drop in replacement for our needs.