It's the year 2026, and at Flying Circus our NixOS platform still runs on scripted networking. But the writing is on the wall: scripted networking's days are numbered, and the time is coming where we need to consider replacing it.

The journey which brought us here goes back to a major architecture change in our datacentre networks starting in 2023. We couldn't meet all of the operational requirements for this migration using systemd-networkd, so we dug our heels in and put our effort into scripted networking instead, adapting and improving it in order to robustly handle complex, dynamic network configuration.

In this talk I'll reflect on some of our decisions as the rest of the world has moved on, and discuss some of the technical details like interface renaming, configuration convergence, and the dizzying array of systemd unit dependencies which are involved. It's not been all smooth sailing, and some sharp edges have periodically come back to bite us. And ultimately we have to ask ourselves: where do we go from here?