I'm one of the core developers of ADBC (Arrow Database Connectivity). This started as a joke — what would it take to call ADBC from COBOL? Turns out, not much. COBOL's fixed-layout record tables and Arrow's columnar arrays make a lot of the same bets about how to represent typed values in memory. The post walks through the architecture and what surprised us. Repo with runnable GnuCOBOL demos for SQLite, DuckDB, and Snowflake: https://github.com/columnar-tech/adbc-cobol