Age and Coding - Will I Be Okay at 40?

Oldest on the Team

I counted the ages of the eight developers on our team.

27, 28, 29, 30, 31, 32, 33. And me, 35. The oldest on the team. Two years ago I was somewhere in the middle. Now I'm at the far end.

Every time I see a job posting that says "young and dynamic team," I get this weird feeling. Does their definition of "young" include me? (Probably not.)

The "Retire at 35" Thing

There's an unspoken legend in the Korean IT industry.

Developers either transition to management after 35 or fade into irrelevance. Coding speed peaks in your 20s. Stamina is better when you're young. Adaptability to new tech declines with age.

Is any of that actually true?

Linus Torvalds is still writing code in his mid-50s. Silicon Valley is full of active senior engineers in their 40s and 50s. The "retire at 35" thing is a uniquely Korean myth. It's an optical illusion born from a country with a short IT history, where there simply weren't many role models of developers over 40.

But knowing it's an illusion doesn't make the anxiety go away.

Slower, but Fewer Rewrites

Sure, my coding speed might have been faster in my 20s.

But if we're judging code purely by speed, AI already beat all of us. As experience accumulates, you spend more time thinking before writing code. You develop a sense for which design decisions will cause problems six months down the line. You stop repeating the same mistakes. You don't panic when production goes down.

These things are hard to put on a resume, but they carry real weight on a team. Writing less code that needs fewer fixes is faster than writing fast code that constantly breaks. It takes years of trial and error to truly internalize that truth.

Honestly, My Stamina Has Dropped

Let me be honest -- my stamina has clearly declined.

An all-night coding session wrecks the next two days. I don't have the same weekend energy for side projects. When a new framework drops, my first reaction is "another one?" Fatigue beats curiosity to the punch.

And sometimes the anxiety creeps in. When my 28-year-old colleague rattles off the latest tech like it's nothing, and I realize my knowledge froze three years ago. But that 28-year-old will feel the exact same thing in ten years. This isn't an age problem -- it's an industry speed problem.

The Direction of Growth Just Changed

Growth in your 20s is vertical.

Learning things you didn't know, doing things you couldn't do, expanding your tech stack. Measurable growth. Visible like GitHub contribution squares.

Growth in your mid-30s is different. It's about getting wider. Understanding not just technology, but people, organizations, and business. Gaining deeper understanding by explaining things to juniors. Seeing systems instead of code.

The direction of growth changed -- it didn't stop. But this kind of growth is harder to see, so you start doubting yourself sometimes. (That part gets lonely.)

Still Writing Code Today

Will I be okay in my 40s?

Honestly, I don't know. But five years ago I worried about whether being a developer in my 30s was okay, and here I am, doing just fine. I'll probably have the same worries five years from now while writing the same kind of code.

I type. I write code today. Maybe slower than my 20-year-old self. But more solid.

That's enough, I decided to believe today.