SharpCell.Grid running in the browser. Try it with your own .xlsx: live demo

Disclosure: SharpCell's code was written by Claude Code, with me directing it. This article was drafted with Claude too, and edited by me. Which is kind of the point of the article. Originally published on Medium .

As we know, sooner or later every .NET project gets an .xlsx with formulas in it. A pricing model from the finance team, a template the customer fills in, a file that is, honestly, the real specification of the business logic. Reading the cells is easy. Calculating them is where the fun starts: change one input, and every formula that depends on it has to be recalculated, and the result has to be what Excel shows.…