[matthewmacleod]

Also neither here nor there, but engineers are expensive and gigabytes are cheap. There exist many circumstances in which the architecture which requires 12 GB of RAM is a defensible engineering tradeoff versus the one which takes 5 MB.

This is a vital point — everybody wants to shoot for lovely, elegant systems that use minimal resources. But resources are astoundingly cheap; we've got a bunch of servers with 128GB of RAM, and you can get these for around £100 a month each. That's less than two hours of developer time. If using Ruby in place of another language saves you that much time—or even just makes you a little happier—it's probably worth it.