Having done a lot of work with financial firms in the past, I found that they're incredibly wary of any agency having access to any of their data.

As a consequence any telephony or messaging product we built had to have a self hosted deployment as part and parcel of our product offering. This meant we usually went for a Java backend which gave us great packaging and install tools. It also meant we had .deb and .rpm packages for all our products.

I can't tell you how much those packages helped. Once you start bundling up your software deployments as proper versioned installation packages you become quite spoilt in the DevOps department - it's hard to use Chef/Puppet or Vagrantfiles for software installations now!