https://xlsong-blog.vercel.app/ Recent content on Xiaolong Song Hugo en-us Sun, 24 May 2026 10:00:00 +0200 https://xlsong-blog.vercel.app/posts/nl-transport-pulse/ Sun, 24 May 2026 10:00:00 +0200 https://xlsong-blog.vercel.app/posts/nl-transport-pulse/ Terraform, Airflow, BigQuery, dbt, and Streamlit answering one question: why is my train late? https://xlsong-blog.vercel.app/posts/ai-tool-for-an-ai-skeptic/ Mon, 06 Apr 2026 10:00:00 +0200 https://xlsong-blog.vercel.app/posts/ai-tool-for-an-ai-skeptic/ A cron pipeline, one caged LLM call, and why boring architecture won over a skeptical scientist. https://xlsong-blog.vercel.app/about/ Mon, 01 Jan 0001 00:00:00 +0000 https://xlsong-blog.vercel.app/about/ <img src="https://xlsong-blog.vercel.app/images/avatar.jpg" alt="Xiaolong Song" width="180" style="border-radius: 50%;" /> <p>I&rsquo;m Xiaolong Song, a data engineer based in the Netherlands.</p> <p>I build data platforms and apply LLMs in production. Recent work includes PySpark pipelines processing 120M+ rows per day, lakehouse architectures on GCP and Microsoft Fabric (Delta Lake, BigQuery, dbt, Airflow), and AI engineering: LLM cost engineering, prompt caching, and coding-agent workflows.</p> <p>Before data, I spent four years as an infrastructure engineer, then moved into this field through an MSc in Statistics and Data Science at KU Leuven. That detour shaped how I work: data problems are engineering problems, and they deserve versioning, tests, and honest trade-off analysis.</p>