[mherdeg]

A little over ten years ago I worked in the Excel Services team that makes the consumer-visible Excel Web App and also the SharePoint-integrated Excel Services product (server side processing accessible via API or web UI).

I loved seeing the genuine joy our PMs had whenever they found an honest to goodness calc bug and could get it reproduced and fixed in The State Machine. It was also a delight to see the web app approach parity with the desktop client experience -- we got to listen to a wide swath of users and build out the stuff we thought would be most useful to the most folks. And I loved our group PM's insight about what the heck Excel could be good for versus purpose built BI tools, other web sheet apps, pure SQL, etc.

This is a very fun kind of product to create and it's awesome that you were able to ship it in a way people could use!