Where Will Senior Developers Come From?

All year I’ve been writing about the top arm of the K-shaped developer market: experienced developers, armed with AI, are more productive and more valuable than ever. I stand by every word.

This post is about the other arm, because I think the industry is making a mistake there that it’ll regret in ten years.

The junior squeeze

Job postings for software developers are still well below where they were before the pandemic, and the drop is sharpest at the entry level. Every week I hear from bootcamp grads and CS graduates who’ve sent hundreds of applications without a single interview. Companies that used to hire a cohort of juniors every year have quietly stopped.

The logic, when anyone says it out loud, goes like this: the work we used to give juniors - small features, bug fixes, tests, boilerplate - AI can now do, and a senior developer can supervise it. Why pay for a junior and spend senior time training them?

In the short term, for a single company, that logic is hard to argue with.

The problem with the logic

Every senior developer was once a junior developer.

I didn’t become senior by reading about software. I became senior by writing a lot of bad code, breaking things, getting reviewed by people who knew more, fixing things at 2am, and slowly building intuition about how systems behave and how they fail. That took years of doing real work, much of it exactly the “junior work” that companies now want to automate.

If nobody hires juniors, nobody gets those years. And in ten years, when today’s seniors retire, move into management, or burn out, there will be nobody behind them. Just a shrinking, aging, very expensive pool of people who know how things actually work, and a lot of AI-generated code that nobody fully understands.

That’s the tragedy of the commons again. Every company individually benefits from not training juniors. The industry collectively loses its pipeline.

AI makes training juniors easier

Here’s what I think companies are missing: AI doesn’t just make the work cheaper. It makes learning faster.

A junior developer with a good AI assistant has a patient, tireless tutor that can explain any concept, any piece of code, any error message, at any hour. When I started, getting an answer meant finding someone senior who had time, or digging through documentation for hours. Today’s juniors can ramp up much faster than I did, if someone gives them real work and real feedback.

The trick is to use AI as a teacher, not a crutch:

Have juniors explain the AI’s code before they submit it. If they can’t explain it, they don’t submit it.
Review their work in person, not just in the PR tool. Ask why. Ask what else they considered. That conversation is where judgment gets built.
Give them ownership early. A small feature, end to end, including talking to the person who requested it. Ownership teaches faster than tickets.
Let them struggle sometimes. Some problems should be solved without AI, just to build the muscles.
Pair them with seniors who enjoy teaching. Not every senior does. The ones who do are gold.

A message to companies

Hire some juniors. Not as charity - as an investment. A junior hired today, trained well, with AI tools, can be a strong mid-level developer in two years and a senior in five. In a world where senior talent is the scarcest resource in software, growing your own is a competitive advantage.

A message to juniors

The market is hard right now, and it’s not your fault. But some things will help:

Build real things and show them. A deployed app with real users beats a certificate.
Learn fundamentals deeply. SQL, HTTP, the browser, Git, how to debug. These are what let you judge AI output.
Use AI to learn, not just to produce. Ask it why, not just how.
Find seniors to learn from. Communities, open source, meetups. Most experienced developers love helping people who are genuinely trying.
Aim for the top arm of the K. Own outcomes, understand the business, get good at reviewing. Those habits will carry you.

Seniors are made, not hired. Somebody has to make them.