Yes, of course.
Nope, every time I looked into it, it looked to introduce more problems than it solves. Having a load balancer that drains the connections to the old VM / pod on deploying a new one has worked super stably with complete zero-downtime so far (though it does require slight trickery sometimes f.ex. if you keep a local GenServer state and that controls rate limiting to a sensitive resource you are very likely to temporarily go over the rate limit due to lost state).
Mix, Docker, docker-compose and scripts to check for container / pod readiness & liveness. Also for initial DB setup and seeding (the PostgreSQL official Docker container allows you to drop scripts into a special directory and the DB will execute them all before announcing it’s ready).
Web / API and Telecom. The main one I am working on right now is listening for messages on a broker’s queue (in this case Kafka but we are researching alternatives) and then communicates with SIM cards worldwide.
