[jedreckoning]

Hi HN — I built fin123 after repeatedly seeing trading desks rewrite spreadsheet logic inside application code.

Typical workflow today:

Analyst builds Excel model Developer rewrites formulas in Python / JS Application table

That rewrite step is painful and error-prone and endless.

fin123 takes a different approach: the worksheet itself is the artifact:

Worksheet spec... Compiled worksheet (deterministic artifact)... Application embeds the viewer

Design goals:

- deterministic builds - offline computation - finance-safe joins and lookups - Polars-backed table evaluation - explicit lifecycle: commit, build, verify, release

The core engine is open source (Apache-2.0) and runs fully locally.

Happy to answer questions.