wroclove.rb 2026 lightning talk comparing CSV-parsing options in Ruby: stdlib Ruby CSV, smarter_csv, Polars Ruby, and DuckDB. Benchmarks on 1M rows with tasks like regex-validating dates of birth, summing amounts, and scanning for values, all running in Docker. Meta-point: the entire presentation (benchmarks + slides, which broke entertainingly during the talk) was built in about an hour using only codex cli, arguing that creating such demos has never been easier. Results: smarter_csv ≈ 3× speedup over stdlib, DuckDB ≈ 15×, Polars Ruby ≈ 22× (fastest). Memory: stdlib Ruby ≈ 400MB post-load on a 30MB CSV, smarter_csv ≈ 300MB, Polars Ruby ≈ 100MB, DuckDB ≈ 90MB (best). Speaker has used Polars Ruby in production to parse 300MB CSVs in real time within a single request — no caching or pre-calculation needed. Only about two audience members had ever used Polars in Ruby, motivating the talk. All slides, code and benchmarks are in a GitHub repo.