Gunnar Morling Portfolio
Blog by Gunnar Morling, creator of the Debezium change-data-capture platform widely used in streaming data pipelines, and author of Hardwood, an open-source JVM library for reading and writing Apache Parquet files, with posts detailing its performance work and feature additions.
What makes it work
A breakdown of the choices that make this portfolio stand out.
Deep-dive posts tied directly to a maintained open-source project
Posts on Parquet Bloom filters and geospatial support in Hardwood are written by the person actually building the library, so the technical detail reflects real implementation decisions rather than secondhand explanation.
A blog that tracks incremental releases, not just major milestones
Writing about a specific version bump ("Hardwood 1.1.0.Beta1") rather than waiting for a big 1.0 announcement keeps the writing cadence tied to real, ongoing progress.
Coverage spanning both the data-format layer and the systems layer
Posts move between low-level file format work (Parquet) and higher-level systems design (a durable execution engine, idempotency keys) — breadth that reflects working across the full data-pipeline stack, not just one layer of it.
What Data Engineers can take from this
Specific, actionable tips to apply to your own portfolio — no generic advice.
Write about the exact version or feature you just shipped in your open-source project rather than only writing retrospectively about finished work.
Pair low-level implementation posts (file formats, protocols) with higher-level systems design posts to show you operate across the whole stack, not just one layer.
A blog that's a direct extension of an actively maintained project reads as more credible than one that only discusses other people's tools.
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