Jeremias Jaymez: notes on data work https://jjaymez.nl/blog/ Short notes on data engineering, platforms, and applied AI. en RAG Works Better When Your Data Is Already Tidy https://jjaymez.nl/blog/rag-needs-tidy-data.html https://jjaymez.nl/blog/rag-needs-tidy-data.html Tue, 08 Sep 2026 09:00:00 +0000 Every retrieval project I've watched go badly went badly for the same reason, and it wasn't the model. Dagster Pipelines Need Clear Ownership https://jjaymez.nl/blog/dagster-clear-ownership.html https://jjaymez.nl/blog/dagster-clear-ownership.html Tue, 04 Aug 2026 09:00:00 +0000 Nobody's real pipeline problem is the shape of the DAG. It's that a job failed at four in the morning and nobody knew whose it was. Bronze to Silver Is Where Trust Starts https://jjaymez.nl/blog/bronze-to-silver-trust.html https://jjaymez.nl/blog/bronze-to-silver-trust.html Tue, 07 Jul 2026 09:00:00 +0000 Gold layers get the demos. Bronze to silver is where the numbers actually get earned. Iceberg and Nessie Make Data Changes Safer https://jjaymez.nl/blog/iceberg-nessie-safer-data-changes.html https://jjaymez.nl/blog/iceberg-nessie-safer-data-changes.html Tue, 02 Jun 2026 09:00:00 +0000 Git gave application teams a way to try something without breaking main. Data teams waited a long time for the equivalent. Python Logging That Actually Helps https://jjaymez.nl/blog/python-logging.html https://jjaymez.nl/blog/python-logging.html Tue, 05 May 2026 09:00:00 +0000 Most advice stops at 'use structured logs'. The harder part is deciding what's worth writing down before an incident makes that call for you. Data Engineering Best Practices https://jjaymez.nl/blog/data-engineering-best-practices.html https://jjaymez.nl/blog/data-engineering-best-practices.html Tue, 07 Apr 2026 09:00:00 +0000 Five things I keep coming back to. None of them are clever, which is more or less the point.