From looking at their source briefly, I can make two observations: Firstly, their core parsing routine is a state machine not unlike the one found in rust-csv:

From looking at their source briefly, I can make two observations: Firstly, their core parsing routine is a state machine not unlike the one found in rust-csv: https://github.com/wiseio/paratext/blob/master/src/csv/rowbased_worker.hpp#L48 https://github.com/wiseio/paratext/blob/master/src/csv/rowba... Secondly, they do indeed appear to be achieving high parsing speed using coarsely grained parallelism. You can see the code that chunks up the CSV data here: https://github.com/wiseio/paratext/blob/master/src/generic/chunker.hpp https://github.com/wiseio/paratext/blob/master/src/generic/c... It's pretty clever!