[brightball]

Eh...it’s basically a 1 line command with distillery. Another for the rollback capability.

It’s pretty magical. There’s a reason people love it.

Certainly, don’t use it if you don’t need it...it introduces extra complexity...but if you do it’s really hard to beat.

[cryptica]

Having to support two different versions of the Elixir service during the rollout period is risky...

What if something goes wrong during the rollout? For example, if you change the database schema or upgraded your database engine or changed your back end authentication approach, it can break the old code. Then how will you know whether it's a problem with the old code or new code if many nodes are running both?

[brightball]

Those are things you have to account for in any zero downtime deploy situation though. It’s mostly minor changes in how you roll out schema changes.

[dmitriid]

I was mostly listing things you need for Erlang. Elixir, thankfully, hides a lot of things away in much friendlier packages.

That said, even with Distillery, if something goes awry, you'll need to know the warts behind the magic :)