Ludovic Courtès <ludo@gnu.org> writes:

>> - Can we configure the default value?
>
> Yup, just pass ‘--max-jobs=N’ to the daemon.

So I suppose you mean to use the `extra-options` field, e.g.

--8<---------------cut here---------------start------------->8---
(guix-service-type config =>
                   (guix-configuration
                    (inherit config)
                    (extra-options '("--max-jobs=4"))))
--8<---------------cut here---------------end--------------->8---

Ludo, what do you think of Tobias suggestion and have an extra knob to
specifically configure the number of download jobs?

-- 
Pierre Neidhardt
https://ambrevar.xyz/