Over the years I have hired a lot of junior engineers. Some of my favorite moments as a leader were watching them grow: the first time one of them caught a bug I missed, the first promotion, and eventually the goodbye when they moved on to bigger jobs somewhere else. Every one of them climbed the same ladder. The bottom rungs were small features, bug fixes, and test coverage nobody else wanted.
These days I spend most of my time in customer meetings, and I find myself looking around the table and wondering about that ladder. The principal engineers are still there, sharp and opinionated. The junior engineers are there too, but I am less sure how they are getting the reps their predecessors got. Agents now draft most of that bottom rung work, and the data says those rungs are disappearing.
A Census Bureau Center for Economic Studies working paper found that early career employment in the most AI exposed industries fell 12% over the 10 quarters after ChatGPT launched, while less exposed industries stayed stable. The posting data rhymes: the share of tech jobs open to engineers with three years or less of experience fell from 43% in 2018 to 28% in 2024, according to Stanford Digital Economy Lab data summarized by HCAMag. It is tempting to read that as a 2026 hiring story. I read it as a 2031 principal story. The people who should be making staff and principal calls five years from now are the people we are not hiring, or not growing, today.
Be Honest About the Cause
Before we blame the agents, the hype check. Lambert and Schindler (2026) argue that remote work is a real confound. Distributed teams made mentoring harder and quietly made junior hires look riskier, and that shift started before generative AI was writing anybody’s code. HCAMag’s summary of the research puts it bluntly: the real reason junior hiring is collapsing may be your remote work policy.
I think both explanations are partly right, and I do not think it matters much which one wins the academic argument. The outcome for an engineering organization is identical. Fewer early career engineers are getting fewer reps on the kind of work that builds judgment. Whether the rep disappeared because an agent took it or because nobody was in the room to hand it over, the gap in your future leadership bench looks the same.
If you are a leader, that is the useful framing. You cannot fix macroeconomics or settle the remote work debate. You can decide how judgment gets built inside your own team.
What the Grunt Work Secretly Taught
Nobody designed the junior engineer curriculum. It emerged as a side effect of the work that needed doing.
Fixing a bug in a service you did not write taught you to read unfamiliar code, form a hypothesis, and test it against reality. Getting paged at 2 a.m. taught you what actually breaks in production, which is rarely what the architecture diagram suggested. Being wrong in code review, publicly and repeatedly, taught you to anticipate the objection before a senior engineer raised it. Writing the tests nobody wanted taught you where the edge cases live.
I saw this happen over and over with the engineers I hired. Nobody became senior because of one big project. They became senior because of hundreds of small, unglamorous fixes that each taught them something about how the system really behaved.
None of that was the point of the ticket. The ticket was “fix the null pointer in the billing job.” The lesson was how systems fail and how experienced people reason about failure.
When an agent drafts the fix, the ticket still gets closed. The side effect does not happen. We removed the work and, without noticing, removed the training program that was riding along with it. I wrote earlier this year that when building gets cheap, deciding gets expensive. The uncomfortable corollary is that we are making deciding more valuable at the same moment we are dismantling the pipeline that produced people who can decide.
The AI Drag Problem
The obvious response is “give the juniors agents too.” That is not a plan, and the evidence says it can make things worse.
Mark Russinovich and Scott Hanselman have described what they call AI drag, as covered in the InfoQ piece on the pipeline crisis. AI tools speed up senior engineers because seniors can steer the model and verify the output. The same tools can slow down juniors, who cannot yet tell a plausible answer from a correct one. A senior reads a generated diff and spots the race condition. A junior reads it, sees green tests, and ships.
I see a version of this in customer meetings. When a design question comes up, the principal engineer in the room usually asks the question that matters: what happens when this fails, who owns it, what does it cost at ten times the load. The junior engineers often have the generated answer ready faster than anyone, but they are not yet the ones asking that question. That gap is not about talent. It is about reps.
Blazity’s analysis of whether coding agents can replace junior developers lands in a similar place: agents can produce junior level output, but they do not produce junior level growth. Handing juniors an agent and walking away widens the gap between the people who already have judgment and the people who need to build it.
Build Judgment on Purpose
If the side effect is gone, the curriculum has to become explicit. Here are four practices I would put in place, each of which uses agents rather than pretending they do not exist.
1. Verification rotations
Make juniors the owners of verification for agent output. They write the evals, review the agent generated pull requests, and sign off on whether the change is correct. A senior engineer cosigns. The junior is no longer writing the fix, but they are doing the harder cognitive task: deciding whether a fix is actually right and explaining why. That is exactly the skill AI drag says they lack, so train it directly.
A simple rotation looks like this:
verification_rotation:
owner: junior_engineer
cosigner: senior_engineer
duration_weeks: 2
responsibilities:
- write_or_extend_evals_for_agent_tasks
- review_agent_prs_with_written_rationale
- log_one_caught_defect_per_week
exit_criteria: cosigner_agrees_on_90_percent_of_calls
2. Incident ownership
Put juniors on call early, in shadow mode, then have them lead the postmortem for an incident they shadowed. Agents can summarize logs, but leading a postmortem forces someone to build a causal story, defend it in front of peers, and propose a change that will survive scrutiny. That is principal work in miniature.
3. Design review apprenticeships
In every design review, assign a junior to write the “alternatives considered” section, especially the rejected options, and defend it live. Explaining why you did not choose an approach is where architectural judgment actually forms. It is also work an agent can draft but cannot own, because the defense happens in the room.
4. Incentives that count judgment
If your promotion packet still rewards PR volume, you are promoting people for the work agents now do. Count architecture decision records, evals that caught real defects, postmortems led, and design alternatives defended. Guillermo Power makes a related argument about what might actually work: the organizations that keep growing talent will be the ones that change what they measure.
None of these practices is expensive. Each one costs senior time, which is the point. Senior time spent growing judgment is the investment; agents are what free it up.
A Test for Principals
Before you set 2027 headcount, try one exercise: list every engineer with less than three years of experience on your team and write down the last time each of them owned a decision that could have gone wrong. If that list is short or empty, the agents aren’t the problem. The problem is that nobody is designing the pipeline.
The agents will keep getting better at junior work. Whether anyone gets better at principal work is still up to us.