# Notes from the build

> Notes from building a data stack in Mojo — durable execution, file formats, and what the measurements actually say.

Longer pieces about the parts that turned out to be interesting — what the APIs should look like, and what the measurements actually say.

- [Arrow through shared memory, between two processes What each way of handing Arrow data across a process boundary costs, and how to pick one.  19 September 2026](https://magmalake.dev/blog/arrow-through-shared-memory)
- [Arrow Flight to integrate your Mojo code in your legacy pipelines Flight allows you to distribute processing between servers.  16 September 2026](https://magmalake.dev/blog/arrow-flight-as-an-interop-seam)
- [DuckDB and Mojo: a sound example Five audio features as ordinary SQL expressions, computed in Mojo on the bytes of the DuckDB vector. What it guarantees, what it costs to carry, and where the speed actually comes from.  11 September 2026](https://magmalake.dev/blog/duckdb-and-mojo-a-sound-example)
- [One source tree, two Mojo versions Mojo 1.0 and nightly will diverge over time. Here is one possible pattern on how to handle that.  8 September 2026](https://magmalake.dev/blog/one-source-tree-two-toolchains)
- [The parquet.mojo performance bar Flat columnar reads are ahead of pyarrow on one core and on four, writes are at parity, and nested data loses before threading comes into it.  5 September 2026](https://magmalake.dev/blog/parquet-mojo-against-pyarrow)
- [Multithreading with origins in Mojo 1.0 The typed context in the previous post erased the origin of the state it shared, and the compiler destroyed that state before the threads started. Here is the one-line fix, the library change behind it, and a test harness that holds the compiler to what it catches and what it does not.  3 September 2026](https://magmalake.dev/blog/multithreading-with-origins-in-mojo)
- [The parquet.mojo correctness bar Our native Parquet reader now reads 66 of the 69 files in Apache's own corpus.  2 September 2026](https://magmalake.dev/blog/how-far-parquet-mojo-is-validated)
- [Writing async-like code in durable execution Write straight-line Mojo. If the process dies halfway through, it resumes without redoing the work that already succeeded. Here is the whole API, and how to handle every way a step can fail.  2 September 2026](https://magmalake.dev/blog/writing-async-like-code-in-durable-execution)