If you work in SharePoint, you'll probably run into a situation where you need to bring a bunch of items into a list. In our on-prem SP2010 farm, we did this using Datasheet Mode, which wasn't fast, but was reliable. The Quick Edit function in SharePoint Online is better in some ways (like working with browsers other than Internet Exploder), but is horribly slow, prone to crashing the browser session, and worst of all, unreliable.
There are other methods to do this, including third-party apps and Powershell, but apps still have to work inside of Microsoft's limitations and Powershell is...well, Powershell. So, then I had this crazy idea.
It still took me about 10 mintues to set up the Excel file and the App, then about 7 minutes for the data (1,601 rows of it) to write into the list. This was after about an hour trying other methods and hitting a wall every time.
Now, the next project on my "when I have some free time" list is taking this idea and figureing out how to incorporate it into the existing Apps that work with other large SharePoint data imports in a way that is actually end-user-friendly.
Thanks for your sharing here.