I’m Yuwei.

Software engineer, ten years in. Los Angeles.

For the last six years, I’ve led engineering on marketplace vendor billing — a high-stakes financial system where a typo costs real money. The systems I’ve owned have processed close to $1B in vendor payments across thousands of vendors. Some of that was inherited; the most recent chapter, I built from scratch.

I started in 2015 doing full-stack web work at Zobrist Consulting on B2B commerce platforms. Joined Houzz in 2018, on checkout and payments. Eventually I led whole subsystems: product ads, supplier BI dashboards, vendor integrations (EDI and API), order creation, billing and accounting. The team trusted me with the gnarly parts — things like a 1,500-line checkout function I refactored to decouple fraud detection into an async pipeline, killing a class of synchronous errors that had been hurting checkout UX for years. Became the go-to engineer for the parts of the system where vendors actually got paid.

When Houzz spun out the marketplace business as Shophouzz under Cart.com, I went with it. I started using Cursor in June 2025 to write billing-workflow scripts during the platform transition — that was my real introduction to AI-augmented development. Six months later I was rebuilding the whole billing system from scratch, solo — it started as an offline rebuild and is now live, serving production traffic. ~700K lines of code shipped over six months, ~83% AI co-authored. Cursor first, then Claude Code from February 2026 onward. The agents aren’t autopilot — they’re force-multipliers, and a lot of the harder business logic is still hand-written. But I’m shipping work as a one-person team that used to take three engineers two years.

What I care about now: I want to build software the way it’s actually possible to build it in 2026, not the way it was possible in 2018. Go all-in on AI; keep it harnessed. Use agents thoughtfully, evolve the workflow as the tools mature, be honest about what they’re good at and where they break — and never let them ship without a human on the trigger. I think the engineering teams that internalize this will be doing the most interesting work of the next decade.

Currently engineering marketplace billing at Cart.com. This site is where I share what I build and how I think about the craft — not a job board. If you want to talk engineering, AI tooling, or trade notes on building thoughtful systems, reach out.