We Rewrote JSONata with AI in a Day, Saved $500K/Year (https://www.reco.ai/blog/we-rewrote-jsonata-with-ai)

Bit of a hyperbolic framing but this looks like another case study of vibe-porting, this time spinning up a new custom Go implementation of the JSONata (https://jsonata.org) JSON expression language - similar in focus to jq, and heavily associated with the Node-RED (https://nodered.org) platform.

As with other vibe-porting projects the key enabling factor was JSONata’s existing test suite, which helped build the first working Go version in 7 hours and $400 of token spend.

The Reco team then used a shadow deployment for a week to run the new and old versions in parallel to confirm the new implementation exactly matched the behavior of the old one.

Tags: go (https://simonwillison.net/tags/go), json (https://simonwillison.net/tags/json), ai (https://simonwillison.net/tags/ai), generative-ai (https://simonwillison.net/tags/generative-ai), llms (https://simonwillison.net/tags/llms), agentic-engineering (https://simonwillison.net/tags/agentic-engineering)