The role AI actually eliminates

Everyone keeps predicting that AI eliminates the junior engineer first.

I think that prediction aims at the wrong rung of the ladder.

Maya is the best mid-level engineer on her team. Give her a ticket and she ships it: clean code, good tests, on time, every time. For six years that reliability made her indispensable. Then the two juniors on her team got Claude Code, and within a month they were closing tickets at her pace.

The thing Maya was great at became the thing everyone is great at. Overnight.

To see why this lands on the middle rung specifically, ignore the years attached to each title and look at what each rung is for.

A junior engineer is paid to learn. That growth path is human, and AI does not remove it.

The pinnacle of mid-level development is successful execution. Hand over a clear spec, get back working, production-grade code. Reliable translation of a defined problem into a working solution: that is the rung's entire identity.

A senior is paid for judgment within ambiguity. Not judgment in general: judgment where the spec does not exist. What to build. What to cut. What breaks at 2 AM, and whether it is worth preventing.

Now line those up against what AI actually does. Give a coding agent a clear spec, a well-organized codebase, and context about your team's practices, and it produces the implementation. Execution is the part AI is best at. The middle of the ladder got automated. The rungs on either side did not.

And the consequence is bigger than one rung folding. If AI gets a junior close to mid-level execution quality, the distance between junior and senior is not as wide as it has been. The traverse that used to take years of grinding through tickets now runs more directly: from learning what to build, toward deciding whether to build it.

Here is the cruel twist. The tool feels slow when you are fast. A proficient engineer who can type the solution in twenty minutes experiences the AI loop as friction, so they wait. A junior has no speed to defend, so they adopt on day one. The engineers whose role depends most on execution are the slowest to pick up the tool that resets it.

But the trap and the door are the same tool. The mid-level engineer who fully embraces AI keeps solid execution, now with the tool doing the typing, and frees bandwidth for the hardest habit separating the middle of the ladder from the top: the pause. Stopping to ask why this is being built. Challenging whether it should be built at all. That used to be hard to practice. You cannot challenge your colleagues all day. You can challenge the AI all day long.

That is what Maya did. She stopped racing the tool, started writing the specs the juniors' AI built from, cut a feature that looked urgent and was not, and learned what breaks at 2 AM. Six months later her name was on fewer commits than anyone on the team, and nothing shipped without her. Then the title caught up.

In Course 1 I teach the seven building blocks because they are the vocabulary of exactly this: owning problems instead of tickets. The rung was never the job. The judgment was.

You do not climb by writing more code. You climb by owning the problem the code is for.

One more thing, because it is the practical version of this whole letter.

The argument above says you grow by challenging the AI, not by accepting its code. So I built a tool that makes the AI challenge back. It is called Scaffold, it is free and open source, and here is what it actually does:

Before it writes a line of code, it asks what you think should change, and why. Then it shows its own plan as a diff against yours: what you got right, what it would do differently, and the concept behind each gap. When you genuinely disagree, it will not move until you have argued it out. It keeps a running wiki of what you have actually proven you understand, kept separate from what it merely knows, and every commit ends with a short report on the code and on you. The record of your growth lives on your machine and nowhere else.

It has been tested into the ground by simulated engineers. Now I want ten real ones to break it.

If you have Claude Code and a codebase you actually work in, run Scaffold on real work for two weeks and tell me the one moment it annoyed you most. Make it to the end and Course 1 is on me.

Want in? Reply with "I'm in." That is the whole application.

P.S. The objections I could not fit here (where will seniors come from, what about code quality, and the one defense of the mid-level role that almost works) are in the extended version: https://systemthinkinglab.ai/newsletters/ai-will-eliminate-an-engineering-role-it-is-not-the-junior-one/

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