It definitely violates DRY but if you keep passing the JWT down the call chain, you can do redundant permission checking in your business layer. Now the reason

It definitely violates DRY but if you keep passing the JWT down the call chain, you can do redundant permission checking in your business layer. Now the reasonable response to the above is that this should be happening in a dedicated authn/z concern - and that is correct! But when paranoia is called for, it's not unreasonable to have redundant checks in logic where authz is critical.