How to convert an Excel spreadsheet to Python without rewriting your formulas
A step-by-step guide to turning an Excel model into a tested Python package: tag inputs and outputs, generate the code, and prove it matches the workbook.
Blog
Notes on turning Excel models into production software: how-tos, engineering details and benchmarks.
Moving an insurance pricing model out of Excel: a production checklist
Rating engines often start life in Excel. Here is a practical checklist for turning one into a governed, tested pricing service without losing what the actuaries built.
One billion rows from an Excel model: the 1BRC with generated Rust
We pointed Codcel at the One Billion Row Challenge: a 12 GB CSV, an ordinary Excel workbook, and a generated Rust REST server. Here's how it works and what it measured.
VLOOKUP, XLOOKUP and INDEX/MATCH: what happens to lookups when Excel becomes code
Lookups are the backbone of most business spreadsheets. Here's how Codcel carries them into generated code, from small in-sheet tables to billions of rows.
Guides
Excel vs code for business calculations: when to move, and how
Spreadsheets are a great place to build a model and a risky place to run one. A practical comparison of keeping logic in Excel, rewriting it by hand, and generating code from the workbook.
Turn an Excel spreadsheet into a REST API
Expose the calculations in an Excel workbook as a documented REST API, with one POST endpoint per calculation, in Rust, Java, Kotlin, C# or Go, plus typed clients and an OpenAPI spec.
Turn an Excel model into tools an AI assistant can call (MCP)
Generate a Model Context Protocol server from an Excel workbook, so Claude and other AI assistants call your real calculation instead of guessing at the maths.