LeetCode is your gym now
We’re being told to stop writing code. Hand the ticket to an agent, read the diff, merge, move on. And mostly it works. The code compiles, the tests pass, the feature ships.
But if you never write code by hand again, how long until you forget what good code even looks like?
You don’t understand a system by reading it. You understand it by touching it. Typing it out - deciding what goes where, what calls what, where the data comes in and where it leaves - is what wires it into your head.
The agent is faster, obviously. It writes in seconds what takes me an hour, and half the time it’s cleaner. But speed was never the point of writing code yourself. The point was what the writing did to you.
Put your hands on a system and you carry a map of it in your skull. You know which part holds the whole thing up and which one you can rip out. You know how the data moves, where it slows down, what happens when the network drops halfway through. Not because you sat and memorised it. Because you were the one moving the pieces, and you can’t move a piece without learning what it does.
Now do the other job. You read the diff, it looks fine, it works, you ship it. Do that for a year and something shifts. You can still see that the code works, but you’ve stopped being able to feel why it’s fragile. You read the surface and the structure underneath stays dark.
And that’s the trap. To steer an agent well you need exactly the thing that not-coding takes away. You have to know what good architecture feels like to catch the agent shipping bad architecture. You have to know how data should flow to notice when it’s flowing wrong. The better the tools get, the more your judgment is worth - and judgment is the first thing to rot when you stop practising.
Which is where LeetCode and Codewars come in.
LeetCode I always filed under interview grind - puzzles you drill to pass a screen, useless the day after. Codewars was the opposite: I did it for fun, even when nobody was making me. But that split doesn’t matter anymore. Fun or grind, they’ve both become the same thing - a gym for your programming brain.
You don’t lift weights because you’ll need to deadlift a barbell in real life. You lift so your body remembers how to be strong. Same thing here. You grind a kata not because you’ll ever write that exact function at work - the agent will - but because the reps keep the muscle alive. The one that breaks a problem into parts and reaches for the right shape without being told. The muscle that knows, in your hands and not just your head, how code fits together.
Twenty minutes. A small problem, no agent, no autocomplete, just you and an empty function. The answer doesn’t matter. You’re doing it to keep the wiring intact.
The developer who still writes code by hand isn’t being nostalgic. They’re the one who can still tell when the machine is wrong. In a world where everyone can generate code, that’s the skill worth having.
Let the agent type. Just don’t let it do your thinking - because one day it’ll be wrong, and you’ll need to be the one who notices.