When Template Haskell or multiple packages join the fray, compilation times can get quite high, quite quickly. This is more an experience with stack, as there a

When Template Haskell or multiple packages join the fray, compilation times can get quite high, quite quickly. This is more an experience with stack, as there are means for incremental caching to avoid full rebuilds when a top-level change is made - nix-build and bazel being a few. It doesn't help that sometimes stack can't tell if it should rebuild TH or not - a long standing bug.