I'm Andy Wang, a senior product engineer based in Xi'an (UTC+8). Building web software since 2005, working primarily in Ruby on Rails since 2008, remote with US and European teams since 2011. Recent work: key contributions to Adwave's production AI workflow, platform design and development for EquiDeFi, and my own products through Tiny Prism.
Now / what I'm working on
Key contributions to a production workflow that turns website and business inputs into advertising creatives. My part is the product system around the model: multi-stage flow, application state, retries, and behaviour a user can rely on.
My public product: an I Ching reflection tool built on traceable casting and verifiable computation — eight methods, an inspectable computation trace, and a deliberate non-fortune-telling stance. English, 简体中文, 繁體中文.
Long-term ownership of production Rails codebases — payments, scheduling, marketplaces, content and admin surfaces — plus LLM features built on RubyLLM and Hotwire-driven portals that feel native without leaving the monolith.
About
I've been a Rails developer for about as long as Rails has been a thing people did for a living — and a remote one for almost as long. Most of what I do is the unglamorous, careful work of turning business rules into systems that keep working while they change.
I started writing code professionally in 2005, building projects for Japanese customers in VBS, C#, Java, and HTML. In 2008 I went all-in on Ruby on Rails at Idapted, leading a small team on a 1-on-1 English-learning platform. Since 2011 I've worked remotely — first at Intridea in the D.C. area on more than ten client projects, then a long string of contracts including Spire Health, imToken, Source Labs, and a multi-year run owning the codebase for a Stripe-powered swimming-lessons marketplace.
Recent work has pushed that foundation into two demanding places. Since January 2025 I've made key contributions to Adwave's production AI workflow, which turns website and business inputs into advertising creatives — my part is the product system around the model: multi-stage flow, application state, reliability, and what the user actually experiences. From July 2024 to June 2025 I did platform design and development for EquiDeFi, whose private-investment workflows span issuers, investors, and professionals across onboarding, documents, agreements, and operational states. The two overlapped part-time from January to June 2025, with responsibilities kept separate. Neither is my product — the interesting part is what it takes to make systems like these dependable.
I'm also the founder of Tiny Prism LLC, my founder-led product and engineering studio, and the creator of HexagramCast — a public I Ching reflection tool built on traceable casting and verifiable computation, with a deliberate non-fortune-telling stance, in English, 简体中文 and 繁體中文. It's where the whole path stays visible: framing the problem, building it, shipping it, and running it.
Outside work I read, walk, and translate Buddhist sutras — chapters of the Diamond Sutra and the Heart Sutra — for my own practice. A product engineer by day; a life-long learner by night.
What I do
Senior-level Rails engineering, end to end. Greenfield products, long-term ownership of mature codebases, and the awkward middle: the app that worked fine until it didn't.
Models put to work inside real products, not demos: multi-stage workflows, structured outputs and tool calls, async state, retries and fallbacks, human review, evals, observability, cost control. On the Rails side, RubyLLM and its ecosystem are home ground.
Stripe integrations with real business logic — subscriptions, marketplace splits, refunds, dunning. Several years on a swimming-lessons marketplace combining coach availability, complex course rules, payments, and admin reporting.
Systems where the hard part is roles, permissions, documents, and state: private-investment workflows, vendor marketplaces, room and meeting operations across a large building, configurable customer-facing portals.
Rails content systems with sprawling third-party reach — publishing into Google Docs, Medium, HubSpot, and WordPress. Clean REST & GraphQL APIs, plus the messy half: webhooks, retries, and assorted vendors who consider documentation optional.
React for the parts that genuinely benefit from React; Hotwire/Turbo for the parts that don't. I don't believe in framework loyalty — I believe in shipping the thing.
A short timeline
Stack
Words
Andy is very intelligent and has a strong understanding of web development principles. I've always been comfortable handing him a project and knowing that he'll be able to solve even the most difficult problems.
Andy is an experienced software engineering professional that excelled at tackling every single challenge thrown at him. I had witnessed him pick up several different codebases and be instantly productive.
A superstar with a finely honed ability to deliver well-tested, well-executed code. Consistently amazed with his ability to think creatively to solve hard problems with the resources on hand — usually while juggling two or more projects at once.
Any kind of bug or feature he took on was done quickly and done well. He communicated very clearly when he needed clarification. I never needed to worry that something would get done.
I'm most useful where there are real users, non-trivial workflows, and a codebase that must keep running while it changes. Open to selected senior product engineering, Rails, and production AI engagements — usually one or two at a time. UTC+8, but well practiced at meeting US/EU teams in the middle.