Full-stack with AI agents · ten years in the field

Theo Yu 于学龙

Ten years of building software, now working full-stack with AI agents.
Orbiting around me: work made with teams, and apps of my own.

All projects

6 team projects · 4 independent apps · select to open

01 TSX Independent · macOS Released · MIT open source
02 Lumax Clip Independent · macOS On the Mac App Store
03 Lumax Tempo Independent · macOS On the Mac App Store
04 Pennilo Independent · iOS On the App Store
05 Xuanwu AI Network Control Platform Team projects · Tianchi 2025 — Present
06 Youlian Cloud Team projects · Tianchi 2025 — Present
07 Zhijie Matrix Team projects · Tianchi 2025 — Present
08 Fatianshi website Team projects · Fatianshi H2 2020 — Early 2025
09 Fatianshi Contract Library Team projects · Fatianshi H2 2020 — Early 2025
10 LegalOffice Team projects · Fatianshi H2 2020 — Early 2025

Project details

TSX · Dark Liquid Glass — Actual UI · demo text

Independent

TSX

Native macOS translator

macOS · Released · MIT open source

A native macOS translator: select text or capture part of the screen, get the result in a floating panel, and edit in both directions — with Apple Translation or services you configure yourself.

What’s confirmed

Native macOS app, released on GitHub and open source under MIT.
Entry points: text selection and screen capture; results in a floating panel with two-way editing.
Translation: Apple Translation, or other services you choose to configure.

Worth talking about

Selection & capture
Staying in the flow
Two-way editing
System vs. external services

Product page Source on GitHub

Real captures of TSX 1.3.4 with demo text; the page behind the dark glass window is this site’s English version.

Independent

Lumax Clip

Clipboard manager

macOS · On the Mac App Store

A clipboard manager for text, links, images, audio and file references — with search, categories, favorites and a keyboard-first workflow.

What’s confirmed

A macOS app, available on the Mac App Store.
Handles text, links, images, audio and file references.
Search, categories, favorites, and a keyboard path from summon to paste.

Worth talking about

Search
Information hierarchy
Keyboard workflow
Localization
Local-first data

Product page Mac App Store

Actual app UI with isolated demo data.

Independent

Lumax Tempo

Menu bar calendar & time

macOS · On the Mac App Store

Calendar, reminders, world clocks and desktop notes from the menu bar — a whole day, organized in a compact space.

What’s confirmed

A macOS menu bar app, available on the Mac App Store.
Calendar, reminders, world clocks and desktop notes.
Light and dark appearance (some features shown are Pro).

Worth talking about

Dense information
Progressive disclosure
Native permissions
Time & calendars
Light & dark

Product page Mac App Store

Actual app UI with demo calendars and reminders; screenshots include Pro features.

Independent

Pennilo

Personal finance

iOS · On the App Store

An independent personal finance app: records stay on your device, photo recognition drafts an entry for you to confirm before it is saved, and iCloud sync is optional.

What’s confirmed

An iOS app, available on the App Store.
Local records; image recognition creates drafts that you confirm before saving.
Optional iCloud sync.

Worth talking about

Drafts vs. saved records
Local data, optional sync
Native experience
Recoverable actions

Product page App Store

The home screen is a real capture with synthetic sample records; the other three are App Store artwork.

Team projects CurrentUI rebuild · AI assistant

Xuanwu AI Network Control Platform

SDN operations & service provisioning

Tianchi · 2025 — Present

Tianchi’s platform for running its SDN and provisioning services, with real-time traffic and topology monitoring. I rebuilt Xuanwu’s entire UI, added a live AI-assistant chat that reads the data on the current page, added an access-IP management system, and maintain features across the front end and back end.

What’s confirmed

SDN operations and service provisioning, with real-time traffic and topology monitoring.
Rebuilt the entire UI.
Added a live AI-assistant chat that uses the current page’s data as context.
Added an access-IP management system; maintain features across the front end and back end.

Worth talking about

An assistant that reads the page you’re on
Rebuilding a real-time monitoring UI
IP management
Owning front end and back end

The sign-in page is the real UI: the contact number is replaced with the placeholder 400-8888-888, and no account or password appears.

Illustration · not product UI

Team projects CurrentArchitecture to launch

Youlian Cloud

Self-service ordering for overseas businesses (海外优连云 · unofficial translation)

Tianchi · 2025 — Present

An open ordering site for overseas business customers: pick a location on a map to find matching services, browse resources, submit tickets and provision in one click. I set up the architecture and built it, worked with requirement owners and engineers across the stack, integrated Stripe for international payments, and took it through deployment to launch.

What’s confirmed

An open ordering site for overseas business customers.
Map-based service search, resource browsing, tickets and one-click provisioning.
Owned the architecture and development, integrated Stripe international payments, and deployed it.
Worked with requirement owners and engineers across the stack.

Worth talking about

Map-based service search
Stripe international payments
From architecture to launch

Illustration, not product UI.

Illustration · not product UI

Team projects CurrentAI agents

Zhijie Matrix

Private AI agent platform for enterprises (智界矩阵 · unofficial translation)

Tianchi · 2025 — Present

A platform that lets companies bring private AI agents into their own work: models run locally and the platform itself is deployed on the company intranet, so data never leaves it. It ships with assistants for general chat, meetings, email, WeCom, documents and knowledge bases, all sharing the same data. One of the projects I work on at Tianchi.

What’s confirmed

Brings private AI agents into a company’s own work.
Models run locally and the platform runs on the intranet, so data stays inside.
Built-in assistants for chat, meetings, email, WeCom, documents and knowledge bases, all sharing data.

Worth talking about

Private deployment
Assistants that share data
Data privacy

Illustration, not product UI.

Team projects Architecture · lead developerLawyers

Fatianshi website

Contracts and legal tools for lawyers

Fatianshi · H2 2020 — Early 2025

A one-stop platform for lawyers: contract templates, contract review, AI analysis, fast search and everyday tools, plus online and in-person courses and community events. I set up the site’s overall architecture and built more than 80% of its pages.

What’s confirmed

Set up the overall architecture and built more than 80% of the pages.
Covers contract templates, contract review, AI analysis, fast search and everyday tools.
Also hosts online and in-person courses and events for lawyers.
The Contract Library and LegalOffice both live inside the site.

Worth talking about

Overall architecture
Building pages at scale
Search & review entry points
Courses & events

fatianshi.cn

A public capture of the home page (October 2026, signed out); the site is run by Fatianshi and keeps changing. The experience is self-reported and implies no institutional endorsement.

Team projects Architecture · developmentLawyers & law firms

Fatianshi Contract Library

10,000+ contract templates

Fatianshi · H2 2020 — Early 2025

More than 10,000 curated contract templates for lawyers; I set up the library’s overall architecture and built it. The library also powers the Model Contract Library website of China’s State Administration for Market Regulation (SAMR), still online for the public — I helped build that site and its data integration.

What’s confirmed

More than 10,000 curated contract templates for lawyers and law firms.
Set up the library’s overall architecture and built it.
Helped build the website and data integration of SAMR’s Model Contract Library; its footer credits Fatianshi’s China Contract Library.

Worth talking about

Organizing and searching 10,000+ templates
A public library for a government agency
Contract data integration

fatianshi.cn Model Contract Library

The capture shows the public home page of SAMR’s Model Contract Library (October 2026, agency marks omitted). The experience is self-reported and implies no institutional endorsement.

Illustration · not product UI

Team projects Add-in developmentWPS / Office

LegalOffice

A lawyer’s assistant on the web and in WPS / Office

Fatianshi · H2 2020 — Early 2025

A lawyer’s assistant: AI contract review, calculators, quick company lookups and many more everyday tools. It lives on the website and also ships as WPS and Office add-ins, which I developed and maintain.

What’s confirmed

AI contract review, calculators, quick company lookups and other everyday tools.
Besides the web version, it ships as WPS and Office add-ins, which I developed and maintain.
Now offered on the website as the Contract Assistant (personal edition), across Word, WPS, web and app.

Worth talking about

One feature set, three hosts: web, WPS, Office
Compatibility across add-in environments
AI contract review

Contract Assistant

Illustration, not product UI; no public captures of the add-ins yet.

About

Taking ideas all the way to finished products.

I’m Theo Yu (于学龙). I’ve spent ten years building software, and today I work full-stack with AI agents, taking ideas all the way to finished products. In four-plus years at Fatianshi I set up the architecture of its website and Contract Library, built more than 80% of the site’s pages, and developed the WPS and Office add-ins for LegalOffice. Now at Tianchi, I rebuilt the Xuanwu platform’s UI and added its AI assistant, took Youlian Cloud from architecture to launch, and work on Zhijie Matrix. Outside work I make my own apps: Lumax Clip, Lumax Tempo and Pennilo are on the App Store, and TSX is open source on GitHub.

In the field: 10 years
Now: Tianchi
Focus: Full-stack with AI agents
Work: 6 team projects · 4 independent apps

Until 2020

Earlier Beginnings

Where the ten years of building began.

H2 2020 — Early 2025

Fatianshi 4+ years

Set up the architecture of the Fatianshi website and Contract Library, built more than 80% of the site’s pages, and developed and maintained LegalOffice’s WPS and Office add-ins; helped build SAMR’s Model Contract Library website.

Fatianshi website
Fatianshi Contract Library
LegalOffice

2025 — Present

Tianchi Current

Currently here: rebuilt the Xuanwu platform’s UI and added its AI assistant, took Youlian Cloud from architecture to launch, and work on Zhijie Matrix.

Xuanwu AI Network Control Platform
Youlian Cloud
Zhijie Matrix

Notes

Notes on why, not just what.

What I worked out while building — and how I work with AI agents.

Working with agents
I built this site with an AI agent
I make the calls; the agent builds and checks. About this site
Interaction
How long should a translation interrupt you?
Where a tool begins decides how far it pulls you from your work. TSX
Information design
Dense information can still feel calm
Decide the reading order first, then how much to show. Lumax Clip
Product thinking
Why confirm after automatic recognition?
Recognition suggests. Confirmation records. Pennilo

Full notes

Working with agents

I built this site with an AI agent

I make the calls; the agent builds and checks.

This site began with a handover: I wrote down the projects, my experience, the screenshots, and what must never be published, and gave it to an AI agent. It came back with three interactive prototypes — a ring of work, a zoomable map, a desk you can pick things up from — and I chose the ring: a person at the center, the work orbiting around. Earlier rounds, a dark version and a set of static layouts, I turned down; each time I pointed at the real page, said what was wrong, and it rebuilt.

The division of labor is clear. What can go public, which phone numbers become placeholders, which responsibilities are confirmed — those calls are mine. The agent turns them into something that runs and can be checked: a static site, Chinese fonts subset to the characters on the page, content that reads in full without JavaScript, keyboard and screen-reader support, and a build that checks links, metadata and the security policy every time.

The biggest change agents bring is that one person can finish a whole product: prototype, build and verify, several rounds, quickly. But an agent won’t decide what’s worth making or what must stay unsaid. I’ve written those boundaries down as standing rules — for commits, privacy checks and releases — and they are now the most important part of how I work.

About this site

Interaction

How long should a translation interrupt you?

Where a tool begins decides how far it pulls you from your work.

TSX starts from the current selection and opens a floating panel with a shortcut; screen capture handles text that cannot be selected. Both paths answer one question: how to stop carrying text into another app.

There are limits. Whether a selection can be read depends on the source app exposing accessible text, and recognition may need correcting. A complete interaction cares for the happy path and states failure clearly — along with what you can do next.

So the result stays in the panel, where both the original and the translation can be edited. A good translation tool should step aside the moment you’re done, and let you get back to work.

Related project · TSX Open project

Information design

Dense information can still feel calm

Decide the reading order first, then how much to show.

Clip puts every kind of clipboard content into one library, with search, types and favorites as ways back in. Tempo centers on the month view, with reminders and world clocks one level away. Both fit very different information into very little space.

The approach: keep frequent actions steady and visible, and reveal rare details on demand. Categories, whitespace and consistent placement orient people better than more decoration.

When an interface quiets down, people find what they came for faster.

Related project · Lumax Clip Open project

Product thinking

Why confirm after automatic recognition?

Recognition suggests. Confirmation records.

Pennilo’s public notes keep recognized drafts separate from saved records. An image is recognized on device and lands as a draft; the user reviews it before saving. That step keeps “what the system saw” apart from “what I chose to record.”

The boundary should show in every state: unconfirmed content should never look saved, failure should never look like success, and discarding a draft should never touch existing records. Clear feedback turns automation into help rather than a new kind of doubt.

It costs one extra tap, and buys a record you’ve actually checked.

Related project · Pennilo Open project

Contact

Have something worth building? Let’s talk.

theoyu8700@gmail.com

GitHub · @TheoYuuu Lumax apps

Personal email