Journey

A record, in order, of what I built through 2026 between the wholesale market and code. Not only the finished results, but the getting-stuck, the fixing, and the relearning.

Four strands that feed each other

They look like separate things, but they actually interlock. A verification method from research checks the data from my day job, that data becomes evidence for a paper, and the whole process gets unpacked in a video.

Wholesale & agricultural data

Tools for the settlement and shipment records piling up daily at Daejeon Jungang Cheonggua Co., Ltd. Where real people and trade are.

Research & AI verification

How much can you trust what an AI returns? Papers are the means; the goal is tools that actually get used.

Content · Sapjil Coding

Only what I've actually built and used, on video. No overstating; if I don't know, I say so.

How I work with AI

Not a tool that only answers, but a partner that looks ahead. More in Approach.

In order

Spring 2026Mar – Apr

First papers, out in the open

I wrote up a method for cross-verifying code review with several AI models and put it on arXiv. It mattered as the first thing I'd "put out into the world."

paper · arXiv

Turning the habit of doubting into a system

I started recording "how I worked" each day and reviewing it. So I don't repeat a mistake, I leave a rule behind every time I get stuck.

method · notes

Extending it to medical code

I tried the same verification method on finding errors in medical coding. Combining several models' outputs caught things a single model missed.

research · medical

Started working with an agricultural research institute

To go deeper into agricultural data, I began talking with a research institute. The point where the day job meets research.

work · collaboration

A second YouTube channel

I opened a new channel to tell the data-side stories separately.

content
May 2026

Open-source security, in earnest

I started finding and reporting memory-safety bugs in open-source libraries — PRs to brotli, snappy, protobuf-c, and jansson, plus CVE reports.

security · open source

"Change the lens and you see more"

With the same code, splitting the review into several perspectives surfaced far more. A moment of confirming something I'd only known in theory.

discovery

Opened this site (manus.mn)

I wanted the scattered things in one place. This is the site you're looking at.

site

Submitted the unified paper to a journal

I pulled the verification work together and submitted it to TACL. It's under review now.

paper · TACL

A tool that verifies citations automatically

I built a tool that checks whether the citations in a paper or document actually exist. That's where it stops — a real source may still not support the claim it's cited for, and judging that is a person's job, not the tool's.

tool · verification
June 2026

Opening it to the world — an English edition

It felt like a waste to keep this site in Korean only, so I opened an English edition with the same content. Now you can read the same story in either language.

site · i18n

"A partner that looks first," in earnest

Without waiting to be told, it looks around and surfaces what I missed every day. How far it's come and where it's stuck, I write down honestly in Approach.

AI · method

Writing down the working principles

Do the free things on its own; always check before anything that costs money. Look broadly rather than narrowly, and act proactively. I'm putting these standards into words.

principles

The day job became a paper

When a price is set at a wholesale market, it isn't only numbers that move — trust and long-standing relationships move with them. I wrote that up and submitted it to the Journal of Rural Studies; it's under review. The first time the research turned back toward the day job.

paper · day job
July 2026

Putting the market's flows on a map

Where produce actually moves from and to, across the country's wholesale markets — on a map rather than in a table. The goal was for the flow to be legible even if you don't read numbers. The last four months are open here.

day job · public

Checking that nothing went missing

We had eight years of records, but had never actually checked whether all of it made it in. Reconciled against the official published figures — no discrepancy. But this only says "our archive is complete," not "the underlying numbers are right" — they come from the same source. That's as far as this check reaches.

day job · data

A medical paper goes out too

A method for finding errors in clinical records by overlaying the judgments of several AI models. Written with a clinician, submitted to ACL ARR, currently under review.

paper · medical

We took down our own scorecard

I had been describing the citation-checking tool with a performance figure measured months earlier. When I went to measure it again, the measurement no longer reproduced. So I removed that number from the public copy. Better to say only what still holds up when you measure it today than to keep a flattering figure around.

verification · honesty

The place the watchdog wasn't watching

I had automated checks so the copy couldn't quietly drift back into overclaiming — but the first screen people actually read sat outside those checks. I widened the scope, then deliberately planted wrong copy to confirm the checks really fire. A green light you can't explain isn't a green light.

method · checks

Still running today

Making a lot turned out to be easier than keeping what you made alive. These are the things running every day right now.

More by area on Work; writing and videos on Writings.