I think I was waiting to share this since I started working on Flow #PHP 😁 Just yesterday with release 0.4.0 it become possible 🤩 This is an example of how easy it is to convert parquet into CSV file by using FlowPHP. The only thing you need to understand is that withEntry function will create or replace existing entry on each processed row. ref() - stands for a reference to a given entry which means that new entries can be created from existing ones. lit() means literal (static value). So here all we are doing is converting nested data structures into JSONs, and objects like \DateTimeImmutable/Uuid into strings. At the end everything goes into a CSV file but can be also any other format or even printed out. On a million rows whole operation takes around 80 seconds with minimum memory consumption. Parquet and CSV are just two among many other supported sources/sinks for your data. Its time to stop using file_get_contents to retrieve file contents, move to ETL! As a bonus, you can find output/input file sizes in the first comment 😁