The solc snap is owned by the solidity team, so they have full access and I'm just contributing testing the candidate releases and moving them to stable. The packaging info is in their repo: https://github.com/ethereum/solidity/blob/develop/snap/snapcraft.yaml
The build and delivery is automated in https://launchpad.net/solidity/+snaps , one pipeline takes every commit from the develop branch and pushes it to the edge channel, the other takes every release and pushes it to candidate.
I've just started playing with geth this week ( https://forum.snapcraft.io/t/request-to-transfer-back-the-geth-snap/9768 ) ), to make it easier for me to maintain the Zeppelin nodes. The packaging and CI is here:
https://github.com/elopio/geth-snap
Travis does all the work here: https://travis-ci.com/elopio/geth-snap
Every night it takes the latest commit from master and publishes it to the edge channel. If there is a new stable release, it publishes it to candidate.
The parity snap is here: https://github.com/elopio/parity-snap , and it works from Travis almost the same as geth: https://travis-ci.org/elopio/parity-snap .
With the exception that there is also a release to the beta channel, and that it already has a very well tested stable release. Parity's Afri has full access.
Here are the builds from travis: https://travis-ci.org/elopio/ipfs-snap/
This one already has plenty of testers for unstable channels, so you just go ahead and enjoy it:
$ sudo snap install ipfs
The ipfs snap is here: https://github.com/elopio/ipfs-snap
It has a special place in my heart because it was my first time maintaining something with that many users 😢 I've used it to experiment with many kinds of automated delivery, and it's now drama-free.