Trade-off: The First Word I Was Told to Carry for Life

Before I understood what engineering was, a professor handed me a word to look up in a dictionary. I've been using it ever since.

A look back — long before any of the tools we argue about now.

Engineering, before I knew the word

In Korea, boys in middle school took a subject simply called "Technology," and high schools offered an elective called "Industrial Arts." Mine taught "Commerce" instead — so my entire pre-college image of engineering came down to a screwdriver, a few nails, and an AM radio kit I'd soldered together. No Lego that I can recall, but I remember playing with science kits, and blowing my allowance on Academy plastic models. The closest thing to "advanced study" was learning to read resistor values off their color bands — black, brown, red, orange, yellow, green, blue, violet, gray, white. That was the whole of my hardware education.

I walked into a computer engineering department without ever really asking myself what engineering was. What I noticed first, honestly, was the gender ratio: about one in ten classmates was a woman, which — after six years in all-boys middle and high schools — was its own small culture shock. Having women as classmates and seniors at all felt like news.

The first word

Our first major course was "Introduction to Computer Engineering," which in practice meant learning C. We could finally touch the machines at school; you did your homework in Turbo C and handed it in on a floppy.

I can't forget Professor Sang Lyul Min, one of the second class our department ever graduated. One day he said, "Let me give you a few fundamental words you'll need for the rest of your life." The first was trade-off. This was before the internet was something you could just search, so I went home and dug it out of a Korean–English dictionary, like a piece of slang I'd never heard.

From that one word I learned three things at once: that there's no free lunch; that this is exactly where engineering parts ways from science; and why the comparison with mathematics would keep coming back. The further I went into my career — and the more decisions I had to actually own — the more that word kept surfacing.

The word that kept coming back

It showed up in my algorithms course, the moment we started weighing time complexity against space complexity. It showed up again and again as I began reading papers, as a way of making sense of the world. If someone asked me today what engineering is — or made me pick a single word for it — I wouldn't hesitate.

I'd say: trade-off.

Adapted from my Korean essay on Brunch: brunch.co.kr/@chaesang/32