I am Jiyu Yan, a software engineer based in the UK. I build practical software for product and business workflows: backend services, integrations, automation, reporting, and internal tools that make daily work easier to understand and maintain.

My strongest work is usually at the boundary between messy requirements and reliable implementation. I like turning unclear operational problems into small systems with explicit data, clear interfaces, and tests that protect the important behaviour.

This site is my professional home on the web. The Dev section collects technical notes and implementation writeups. The Journal section keeps a smaller set of personal essays, translations, and reflective writing.

I spent most of my life in China and moved to the UK for postgraduate study. I have now been here for more than six years, including my full working life as a software engineer.

Outside work, I fence. It suits me for the same reason engineering does: you have to observe carefully, make decisions under pressure, and keep improving after each mistake.

For the more formal version, see my CV.