Never used it. ^.^
All automatically done via my scripts.
Eh, wrote once a long time ago, not touched them since, and heck, elixir's distillery/exrm can generate them for you if you want fresh ones.
Yeeeah I don't trust most things to do this right, since almost none of them do, I'm anal about going over every single option... >.>
Already versioned by OTP's release system.
Ditto, you can start up an older one just as easily as the latest except with an extra argument.
For my erlang servers that is all I do, single command.
I do run a lot of non-erlang stuff though, I just roll them.
Also a single ssh command (and I have a lot of aliases to reduce typing as well).
Automatically managed. ^.^
I use a linux package for that, forgot what it is called, it works well, not touched it in a decade except to add new log file locations as I install new things (since everything likes to do log files different to everything else... >.>).
I've never hated doing that, it is fun! I constantly run out of tasks to do on my servers. ^.^
Well my uptime I better than Amazon's so far, so.... ^.^
I way way overbudget my hardware (hardware's cheap, services are not), never ever needed this, and it ends up much cheaper this way too.
I try to only use software I trust, for the few that I do not I provision stupid things elsewhere and let them run remotely in a read-only setup (*cough*jenkins*cough*, I really really hate that thing, and php forums I host for people that refuse to discourse on over).
I've never had issues, and I use a lot of websockets on some of the sites.
All simple commands over ssh.
I exceptionally VERY hate web gui's for all that, they just make it harder to get stuff done and even doing something as simple as restarting a service involves extra clicks to get to the area, move the mouse, hit a button, pray it is working since you can't see a real-time log, etc... Where as I just type something like
sshcmd blahserver 'cservice roll frontend-nginx' or fully log in or so, of which takes 0-2 seconds to type and hit enter, then I watch the output log streaming by to verify it works. ^.^
I don't even know what is gained with Heroku. At my current job and my last job they are both crazy-VM heavy via VMWare. Have old servers, new servers, hard drive swaps don't go down, generator/battery backups for 48 hours with on-site fuel for both. If a hardware server goes down VMWare auto-migrates it until they can fix it (snoopy needs to be replaced already...). My last job had the 200k+ machines, but my current one has probably 2000 machines at most, the IT department is 3 people (with one retiring next month) with a server room that is just a very cold back room of 6 rack's with a couple dozen servers in them blinking away. Something like Heroku would bankrupt this place (they've checked).