This is more RPC style. I used to prefer this approach because that way you're not constrained to the Nxx error codes of http; it's just request, response. Ha

This is more RPC style. I used to prefer this approach because that way you're not constrained to the Nxx error codes of http; it's just request, response. Having worked in a few companies since then, it seems odd to me now. Besides, all your middleware etc is probably going to use status codes conventionally, so your application code's 2xx error responses will stick out like a sore thumb.