It might be the case that your memory usage data on "aeson" is outdated. Prior to some later releases it was rendering in two passes: first into AST (the Value

It might be the case that your memory usage data on "aeson" is outdated. Prior to some later releases it was rendering in two passes: first into AST (the Value type) than from that into ByteString (Builder). It's likely that your extended memory usage was coming from that. Later they had the `Encoding` abstraction introduced to avoid that 2-pass problem. Both "jsonifier" and "buffer-builder" avoid that 2-pass problem by design.