Projects | Tatsuya Sasaki - Strategy-to-Code Builder | Tatsuya Sasaki

All Work

Case studies in enterprise systems, AI agent organizations, and UX design.

A 12-Agent AI Organization — Designing How AI Works

Web App — 2026

I don't just use AI — I run an organization of it: 12 specialized AI agents with distinct roles, personas, and rules of engagement, governed by a constitutional rulebook evolved over 30 versions. It handles research, drafting, verification, and operations in my daily strategic-planning work, with 18,000+ actions logged over two years of production use.

AI Agent Orchestration · Constitutional Governance · Prompt Engineering

Enterprise Expense Automation — 70+ Daily Users, Solo-Built

Web App — 2026

An expense management platform for a large manufacturing division: automated monthly data collection, reminders, aggregation, and executive dashboards across 90+ organizational units. Solo-designed and built on Google Workspace with defense-in-depth safety architecture. 70+ people use it daily; the investment paid for itself in about a month.

Business Process Automation · Data Pipeline Design · Safety Architecture

PLM Digital Thread — 143K Lines, 430x Faster, Built Solo

Web App — 2024

A cloud-native product master data platform for a flagship door product line: 999 product specifications × 58 attributes, unified across 51 BigQuery tables and serving 4 global factories. Designed, implemented, tested, and documented by one person — with queries 430x faster than the system it replaced.

Data Architecture · Test-Driven Development · BOM Management

UX Foundation

Research and design work from my UX Designer diploma (EQF Level 7) — the training that still grounds how I define problems today.

This Site — A Portfolio That Is Its Own Case Study

Web App — 2025

The site you are reading is itself a production system: migrated from a no-code builder to Next.js on Vercel, cutting hosting costs while gaining full control — then hardened with 6 automated test suites, visual regression, and CI. Maintained through the same AI-native workflow I use at work.

Full-Stack Development · Test Automation · CI/CD

Use Analytics to Inform UX Design - Google Merchandise Store

UX Design — 2023

Your client is an e-commerce platform that sells branded merchandise. They've had a good amount of success despite never having looked at their Google Analytics. They're launching a new campaign on their website soon, and have called you in to help teach them about how their website is performing, and make recommendations.

Data Analysis · Google Analytics · UX Design

Design an App to Combat FOMO - Event Discovery App

UX Design — 2023

Interview people who potentially have FOMO and uncover a problem they have, which you're going to use to inspire an app you're going to create!

UX Design · Persona Creation · User Journey Mapping

Improve an Existing Product - Kopernik Website Redesign

UX Design — 2023

I worked on a project to improve the landing page of Kopernik's website, a non-profit organization in a 2-week sprint cycle. I clarified the website's roadmap related content and tasks, identified by investing mental models and usability, and proposed multiple design alternatives.

UX Design · Information Architecture · Usability Testing

Usability Test Your Dream Vacation - Hoshinoya Karuizawa Website

UX Design — 2022

Identify areas for improvement by looking for hotel websites that may have room for improvement and conducting usability tests

Usability Testing · User Interview · Card Sorting

Conduct Research Around Coffee - Japanese Coffee Market Study

Research — 2022

A multinational brand reached out to me to conduct a study on how people drink coffee. I conducted Ethnography, Competitor Analysis, Created Personas & Journey Map, and Synthesized my Findings.

User Research · Ethnography · Persona Creation