> and let the operating system do all the complex scheduling. So Heroku could spawn workers with a $FD environment variable instead of $PORT and the "complex s

> and let the operating system do all the complex scheduling. So Heroku could spawn workers with a $FD environment variable instead of $PORT and the "complex scheduling" done by the OS _is_ the second routing layer. But really, they could still do a second level routing even outside a single OS as the scale of the distribution is much smaller, so having the routing mesh be aware of the worker availability seems feasible again.