Co-founder & CTO, MARS AI
Turning real-world work problems into products people use.
I spent six years as an IT consultant managing large system development projects, then moved to building products myself. Today I’m co-founder and CTO of MARS AI, where I build and run an AI interior consultation service and a 3D space-design tool.
About
I’m from Korea and also work in Japanese and English. At Deloitte Tohmatsu Consulting, I set up how multi-company development projects tracked progress and issues, and used that data to analyze where each project stood.
I started web development in 2025. Beginning with racu, I’ve been designing, building, launching and running my own services. I use generative AI throughout, in a loop of deciding the spec, checking the result on real screens, and fixing what’s off.
Tools I work with most these days
Career
2026.01 — Present
2019.10 — 2025.10
From PMO to Product
Starting from my project management work, here are the products I’ve built, in the order I built them — along with what carried over from one to the next.
002021–2024
On a large infrastructure company’s system renewal, I used the issue and inquiry data collected in Redmine to track, every week, each team’s planned vs. actual responses, how many new issues and risks came up, and how many days they took to resolve.
I automated the report with an Excel/VBA tool, and it became the main material for the weekly PMO meeting.
This way of looking at projects later became racu’s report feature.
012026.01
A work management tool with PMO-style analysis built in
A work and project management service for small and mid-sized companies in Japan. A business partner in Japan planned the product, and I handled design, development, launch and operations.
On top of the basics — sharing tasks, schedules and owners across a team — I built reports based on the analysis I used as a consultant. Managers can see at a glance how plans compare with actuals, how issues are growing or shrinking, how long work takes, and which tasks are stalled or at risk of missing their deadlines.
A partner shapes the product; I take it from design to operations. That way of working carried straight into MARS AI.
022026.06
Home renovation advice through a conversation with AI
An AI service for homeowners, built with my co-founder, an interior design professional. Starting from photos of a room or a contractor’s estimate, people can see what a makeover might look like, check whether a construction quote is reasonable, and ask about problems in their home.
The conversation helps them sort out what they want, and they can keep asking while looking at the generated images and analysis. Since launch, I’ve been reading real conversations and usage data to improve answer quality and usability.
Aug 2026: 2,415 visitors · Through Sep 19: 578 images generated or edited, 426 estimates reviewed (internal data)
Alongside this consumer service, we built a tool for the professionals who design the spaces.
032026.06
From floor plans to editable 3D spaces
A browser-based tool for interior professionals. It turns floor plans into 3D spaces where you can plan layouts, furniture and materials, switch between plan and 3D views while editing, and walk through the room to see how it will feel.
The 3D engine is written in C# and runs in the browser via WebAssembly. It brings the Unity/C# 3D work I’ve been doing since 2023 — such as the memorial hall guide app below — to the web.
A guide app for a memorial hall. Search for a name, and it shows where that name appears on the wall in a 3D model of the space. Runs on Windows, Android and WebGL.
Unity · C# · Cloudflare Workers
Product page ↗Contact
I’m open to new roles and project inquiries. Email or LinkedIn is the best way to reach me.
rctzzang93@gmail.com