If your workers can hop onto the next task without having to reach out for any additional state or report back to anything synchronously a distributed log/spool

If your workers can hop onto the next task without having to reach out for any additional state or report back to anything synchronously a distributed log/spool/queue/broker works well. If you need light-weight reporting like a status code you can use RPC/reply mechanisms if the broker supports it (e.g. rabbitmq), build your own (custom headers), or use an API/gRPC call. Everything else starts needing some sort of more sophisticated coordination mechanism and gRPC will look attractive for that although there are usually other options as well.