I'm Andy Wang, a senior Rails & AI Product Engineer based in Xi'an, China (UTC+8).
Building web software since 2005, primarily Ruby on Rails since 2008, working remotely with US and European teams since 2011.
My work is the product system around model capabilities โ multi-stage workflows, application state, retries, human review, evaluation and observability โ rather than one-off prompts or demos.
- HexagramCast โ creator and primary builder. A traceable I Ching reflection tool: 8 casting methods (4 traditional, 4 deterministic modern), with the input digest, computation trace, moving lines and classical source layers all inspectable. No fortune-telling, no luck scores. English-first, also in ็ฎไฝไธญๆ and ็น้ซไธญๆ; web, API and browser-extension entry points.
- Rails product systems โ greenfield builds and mature codebases I own over the long term
- Complex business workflows โ payments and subscriptions, lesson/resource scheduling, marketplaces, CMS and multi-channel publishing, data and reporting, admin and operational tooling
- Multi-party platforms โ roles, documents, agreements and state machines, including private-investment onboarding workflows, health-device data portals and vendor marketplaces
- Production AI workflows โ structured inputs and outputs, asynchronous state, retries and failure recovery, human review, evaluation, cost control and observability
- Legacy modernization โ Rails upgrades, test suites, background processing and third-party integrations
I'm most useful where a product has real users, non-trivial workflows, and a codebase that has to keep working while it changes. Happy to talk about senior AI product engineering, Rails systems, production AI workflow integration, and end-to-end product delivery.