I'd argue that it's not really meant for developing software. It's meant for data analysis. When I do my analysis, I am not really concerned with developing the

I'd argue that it's not really meant for developing software. It's meant for data analysis. When I do my analysis, I am not really concerned with developing the script/algorithm. I am mainly concerned with manipulating or visualizing the data. In my opinion, anything that takes more than an hour to process in the notebook should probably be done outside the notebook as an independent script. The only thing that's really missing for me is a more persistent data store in between kernel restarts. If it took more than 5 minutes to run something to transform or process my data, I don't want to have to redo it when I restart the kernel. I think there are a couple of plugins that handle this for you, but it would really be nice if it was implemented natively. The solution right now just seems to be producing a bunch of intermediate files that you reload when you restart the kernel.