shunzz.com

Build with AI. Ship for real.

Spec-driven × AI agents × full-stack delivery. I don't just use AI to write code — I manage how AI works, and I build tools for it.

01

About

Japanese Literature major turned AI-Native Software Engineer (JLPT N1). I ship enterprise systems, ML models and cloud infrastructure with a spec-driven, AI-agent workflow; I write Claude Skills, built an MCP Gateway, and teach the workflow internally. In the AI era an engineer's value is judgment and process design, not typing speed.

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Act 1: An unusual start

Japanese Literature degree, JLPT N1. My career began with language; a six-month AI/cloud bootcamp moved me into engineering. I built AI applications at a startup (content-to-video, LINE avatars and voice cloning) and now work as a Senior Systems Analyst at a retail group's IT subsidiary, spanning data engineering, DevOps and cloud architecture.

Act 2: AI changed how I work

Over the past year I moved my workflow to spec-driven development with AI agents: I adopted the open-source superpowers workflow (brainstorm → design spec → implementation plan → TDD), where AI executes and I review and decide, then tuned it for real projects — one shared AGENTS.md driving two agents, an automated AI code-review loop, and project-specific skills added to the flow (e.g. an Azure DevOps PR skill). With it I independently delivered an enterprise allocation platform (2.5 months), the AI service of a Customer Data Platform, demand-forecasting ML models, a company MCP Gateway in 3 days, and a full app with 62 tests in one day. Every number is in the git history.

Act 3: From user to builder

I don't just use AI tools — I package team domain knowledge as Claude Skills with evals, built the gateway that lets every AI tool in the company reach internal APIs safely, and teach the workflow in internal talks. Next: build something that actually matters.

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How I work

01

Ship products with AI

  • Enterprise retail allocation platform, delivered solo in 2.5 months
  • Career Agent, an AI job-search assistant, live in 3 days with real users
  • A Flask daily-log system in one day, 62 tests
02

Manage how AI works

  • Spec-driven (superpowers workflow): brainstorm → spec → plan → TDD, plus project-specific skills
  • One shared AGENTS.md driving Claude Code and Copilot CLI
  • Automated AI code-review loop until it converges
03

Build tools for AI

  • Self-built MCP Gateway wrapping internal APIs as MCP tools
  • Domain knowledge packaged as Claude Skills with evals
  • Internal talks on prototype-driven requirement alignment

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Featured projects

Suancui (酸脆)

Threads AI roast generator: enter a handle → four roast styles as share cards → share to unlock hidden styles

  • Cloudflare Workers
  • Hono
  • KV
  • React
  • npm workspaces
  • 1 dayto launch
  • 67commits
  • 4packages, each tested

Product thinking and a lesson in failure: Threads' anti-scraping returned 200 with gutted content, so the AI fabricated personalities. "Never fabricate" became a product rule. It spread less than Career Agent — tools that solve real problems travel further than entertainment.

MCP Gateway

Wraps internal enterprise APIs as MCP tools so any AI coding agent reaches them safely through one entry point

  • Python
  • MCP SDK
  • Starlette
  • SQLAlchemy
  • pytest
  • 3 daysto v1
  • 20+test files

Design focus: per-client auth, SSRF protection, encrypted upstream credentials, audit logs with sensitive-parameter masking. Tool catalog lives in a DB — approved tools go live without code changes or restarts.

Enterprise delivery

Retail allocation platform, CDP AI service, demand-forecasting ML, Azure IaC

  • FastAPI
  • React 19
  • .NET 8
  • Google ADK
  • Azure
  • Bicep
  • LightGBM
  • 2.5 moallocation platform
  • 1,100+files
  • 6CDP repos

Delivered solo with AI collaboration at a retail group's IT subsidiary: a 2.5-month allocation platform (FastAPI + React 19), a CDP AI service on a Google ADK pipeline, LightGBM/CatBoost allocation models, and modular Bicep infrastructure.

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Footprints

GitHub
m124578n
LinkedIn
john19980215
Threads
@m23568n
Languages
Chinese · English · Japanese (JLPT N1)