One key thing to check on is what your scalars are doing. Scalars are serialized in the result phase, which happens entirely after the resolution phase. In the past, poorly optimized serialization functions have lead to lengthy post-resolution times.
To dig in further, some additional metrics would be handy. Can you provide an example query document? How large is the result JSON in bytes? How large is the schema (approximated by MyAppWeb.Schema.__absinthe_types__ |> map_size)?
