Sunny Yuen

Frontend Engineer / Full Stack Engineer / Software Engineer · sunny@yuens.me

Full-stack engineer with 7+ years shipping production-grade systems, increasingly at the intersection of TypeScript, AI agents, and the Model Context Protocol. Builds and operates multi-product ecosystems as sole engineer — owning specification, architecture, implementation, QA, and operations end-to-end. Designs AI-augmented systems that are deterministic and auditable by construction: engineering judgment owns what to build and why; AI accelerates the mechanical work.

Skills

Languages: TypeScript, JavaScript, Python, Go, HTML

Frameworks & Libraries: Next.js, React, Hono, Node.js, Tailwind CSS, shadcn/ui

AI & Agents: Anthropic Claude API, Vercel AI SDK, MCP (@modelcontextprotocol/sdk), Claude Agent SDK, OpenRouter

Data & Infrastructure: Supabase, PostgreSQL, pgvector, Prisma, Neon PostgreSQL, Railway, Vercel, GitHub Actions, Zod

Testing: Jest, Playwright, Vitest, RTL, Cucumber

Experience

Self-Employed — Product Engineer (2023–now)
- Architected a comprehensive design system and visual language contract consisting of 12 core components and 13 data fixtures, enforced by Zod to ensure type-safe UI development across a multi-product ecosystem.
- Designed a multi-step property onboarding flow and information architecture that categorizes listings by 'Stay Type,' streamlining navigation through sequential data capture of location, amenities, and high-resolution imagery.
- Developed a responsive, mobile-first component library optimized for 390px viewports, featuring role-specific UI patterns for guests, contractors, and owners including Floating Action Buttons (FAB) and bottom sheets.
- Engineered a grid-based search interface with persistent filter controls for price and capacity, supported by responsive layout shells and a theme proposal system for A/B testing palette variations on live components.
- Defined a 12-component headless contract schema to govern service interactions and a self-sovereign AI agent interface implementing A2A v1.0 and Open Employment Protocol for cryptographic claim verification.
- Functions as sole Product Engineer owning end-to-end specification and production operations, utilizing AI-augmented systems and a 16-case eval harness to gate quality for open-source and SaaS platforms.
Wipro, Inc — Frontend Developer (2023)
- Spearheaded development of a custom web application for LAX airport, enhancing organizational engagement through a dynamic reporting system and organization directory
- Built responsive web/mobile-first UI using Next.js, React, TypeScript, and MUI based on Figma specs
- Integrated Microsoft Active Directory for a searchable personnel directory across airport staff and management
- Launched beta and revamped v1 with authenticated access to reporting via RESTful API endpoints
DesignIt, Inc — Software Developer (2022)
- Enhanced Coherence Design System by adapting type-safe functional components, improving maintainability and performance
- Boosted unit test code coverage from 50% to over 80% using Jest and RTL
- Achieved 0% security vulnerabilities via manual and automated NPM dependency updates
- Collaborated to resolve accessibility issues ensuring compliance with 508/WCAG standards
MetroStar Systems — Frontend Developer (2020–2022)
- Implemented automated accessibility (508) and code quality tests using Jest, Playwright, and Cucumber for the US Census Bureau
- Refactored Farmers.gov Drupal 8 theme using HTML/Sass/CSS/JavaScript, improving efficiency and maintainability
- Developed self-contained Vue.js web applications using Drupal as an endpoint for content management
- Participated in SAFe Agile practices with cross-disciplinary teams
Remine, Inc — Software Engineer (2019–2020)
- Delivered cross-product features for a real-estate intelligence web app serving national brokerage firms
- Contributed to both frontend (React/Redux) and backend (REST/GraphQL) layers
- Designed and maintained global UI components including Modals and Drawers, improving consistency across the application
- Implemented feature flags at the component level to facilitate smoother feature rollouts
- Built styled components within a custom UI library in collaboration with the UX team
DealerOn, Inc — Front End Developer (2017–2019)
- Built data-intensive single-page applications for a client-facing operations management system
- Integrated API endpoints to frontend using Vue.js/Vuetify and collaborated with QA on bug resolution
- Partnered with UX team to iterate over design mocks and built prototypes for user testing
- Utilized Google Charts for data visualization; participated in daily scrums and bi-weekly build cycles

Projects

Artisan Roast Store — Open-source e-commerce store for specialty coffee retailers, built with an AI-native development workflow. (https://demo.artisanroast.app)
Artisan Roast SaaS Platform — Operator control plane for the Artisan Roast stack — manages app installs, subscription plans, billing, license enforcement, and provisioning automation across all tenant shop instances. (https://artisanroast.app)
Resume Agent — A2A-compatible AI agent that represents a professional profile as a machine-queryable JSON API — built for employer AI systems, ATS tools, and personal LLM interfaces. (https://agent.yuens.me)
Brew Guide — Community-powered MCP server that answers 'how should I brew this coffee?' — synthesizes consensus brew parameters from logged experiments with zero LLM dependency. (https://brew-guide-production.up.railway.app)
Resume Agent Web — A talkable, machine-readable face for any resume-agent backend — conversational UI for people, JSON-LD + llms.txt for AI. (https://www.yuens.me)
Open Employment Protocol (OEP) — An open, federated protocol for hiring — a reconciler that poses the candidate and employer positions and settles a net outcome no single party owns. (https://github.com/yuens1002/open-employment-protocol)
Bookie — MCP server for personal & business double-entry bookkeeping — no UI, the LLM is the interface (https://railway.com/deploy/X2T0sN?referralCode=X2mmSS)
StayOps — Chat-first property-operations app for short-term-rental owners, where the agent is the only way state changes. (https://stayops-nine.vercel.app)

Education

Seattle University — Certificate, Web Development (2016)
University of Washington — Bachelor of Arts (1999)

Machine-readable endpoints: profile JSON, A2A agent card, llms.txt. Ask questions over HTTP (POST https://agent.yuens.me/query) or MCP (https://agent.yuens.me/public-mcp, tool ask_candidate).