Re: Time Scale
What you also need is a simple isolated application that is non-critical (no one dies if it screws up) and doesn't need to interact with a lot of other critical systems, and developers of above average competence.
Curiously, replicating the performance of a pile of Google PhDs or university researchers is neither trivial nor inexpensive.
And yes, I did what is now called agile, or RAD, or DevOps developing systems to manage investment strategies for hundreds of billions of dollars... and I've seen how it can fail, as well as succeed, in half a dozen industries.
It is suitable for some purposes, usually user facing relatively undemanding applications, and not at all for mission critical, security critical, reliability critical, highly interconnected (to other critical systems, usually not under your control), safety critical purposes.
It is 'not fit for the purpose' when you are talking Air Traffic Control, SCADA, flight control systems, weapons control systems, emergency communications systems, medical systems, police databases, military command and control, traffic control, railway signalling, systems with mandatory testing and verification regulations, etc. I don't want some enthusiastic, probably relatively inexperienced, DevOps type breaking the control system for the local nuclear reactors, or even the local oil refinery or ambulance/fire/police dispatching system.
We have a cluster of them at my current work, and they are really, really bad about understanding security, infrastructure, standards, troubleshooting in complex environments, and interaction with other systems.
They also have a really high opinion of their own competence and a low one of anyone who actually thinks that Internet and industry standards count for something or who has actually seen some of the other IT 'magic bullets' come and go. Can everyone spell 'Dunning - Kruger'?