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)
- Functions as sole Product Engineer across a live multi-product ecosystem — open-source e-commerce store, hosted SaaS, AI resume agent, and community MCP server — owning specification, architecture, implementation, QA, and production operations end-to-end
- Operates AI-augmented development systems: Claude Agent SDK + Playwright for nightly regression testing and automated repair PR generation; LLM-driven semantic diff for nightly profile sync; deterministic 16-case eval harness for quality-gating AI query responses
- Ships to production-grade standards: type-safe Zod contracts, durable state machines with race guards, 300+ tests, Ed25519-signed git evidence per project, and OEP domain verification (Phases 1–3)
- Designed and shipped a self-sovereign AI resume agent implementing A2A v1.0, public MCP endpoint, and Open Employment Protocol — enabling employer AI systems to verify candidate claims against cryptographically-signed git history
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 — Multi-tenant SaaS layer on top of the open-source Artisan Roast store — managed hosting, billing, license enforcement, AI back office, and provisioning automation for independent coffee shop owners. (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)

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).