You can disagree, but you're still at least partially wrong; if you're using postgres already, adding redis WILL make your system less reliable as you now have another point of failure to deal with (something else to patch, keep up to date, restart, etc, etc). Unless you have super high traffic, low latency requirements - using postgres adds some load, plus saves you having to write code to deal with rollback / race conditions with postgres vs a-redis-queue.