Slowly, but
built to the finish.

Hi, I'm Kim Do-hyun. By day I work as a backend engineer, and by night and on weekends I build small products on my own.

At first I wrote just so I wouldn't forget. A deploy error I barely fixed at 3 a.m., a type error that ate up two hours — if you don't write these down, you're bound to run into them again.

Then I realized: one well-documented failure helps someone far more than ten half-baked success stories.

So 'Sidenote' isn't a finished tutorial. It's closer to a working log — capturing the getting stuck, the backtracking, and the rebuilding, exactly as they happened.