Shopify CEO Tobias Lütke used an AI-powered autoresearch system to optimize the Liquid template engine, achieving 53% faster parsing and rendering with 61% fewer allocations. The optimization involved 93 commits from 120 automated experiments, including replacing StringScanner with byteindex operations and caching integer conversions. This demonstrates how robust test suites enable effective AI-assisted performance optimization on mature codebases.
Background
Liquid is Shopify's open-source Ruby template engine originally created in 2005 and inspired by Django templates. It's a mature project with contributions from hundreds of developers over two decades.
- Source
- Simon Willison
- Published
- Mar 13, 2026 at 11:44 AM
- Score
- 7.0 / 10