Where your next senior engineer is going to come from

Why the training work was automated first, why every number you keep says you are fine, and what rebuilding a rung actually costs.

The work your juniors learned on is the work you automated first.

Skill formed by doing the easy version of hard work, repeatedly, next to somebody doing the hard version. That easy work was the most automatable work in your organization, so it went first — not through anybody's error, but because the properties that make work automatable and the properties that make it teach are the same properties.

This volume is twelve short steps on what that costs, why every instrument you have says you are fine, how to get a measurement before the bill arrives, and what the remedy actually costs. It assumes you have read nothing else in this series.

The spine of the volume: the rungs of the ladder are made of the arriving work. There was never a ladder to fund, only work that happened to teach.

What moves: work of five sizes arrives from the left and becomes the rungs, and a climber goes up them one at a time as they form.

The distinction the whole volume turns on

the quantity	what measures it
what somebody can produce today, with the tool in front of them	everything you keep
what somebody could do with the tool taken away	nothing you keep, anywhere

Those two moved together for about fifty years, so treating the first as a stand-in for the second was a well-calibrated instinct. It stopped being one recently, quietly, and nothing announced it.

The strongest argument against this volume is true, and it gets its own page before the answer. Your juniors really are producing more, and the gain really is largest for the least experienced people. That is a finding about output, and output is not the quantity at issue.

What you can do afterward

Name the work your juniors learned on three years ago and check whether it still reaches a person. Tell reviewing apart from apprenticeship, and stop counting one as the other. Run an afternoon's test that produces a fact about your own team. And price the remedy honestly enough that it survives a budget review.

The mechanism, the test and the four practices are on one page you can print.

Part 1 — what the ladder was made of

01A level you cannot hire for is comingafterward you can state the argument to a peer in a minutereasoning

02How anyone actually became seniorafterward you can describe the mechanism rather than gesturing at experiencesourced

03Nobody owned the training, so nobody missed itafterward you can name the work your juniors learned on three years agoreasoning

Part 2 — why the lower rungs went first

04Why the training work was automated first, by nobody's choiceafterward you can stop looking for somebody who made this decisionreasoning

05What work still reaches somebody in their first yearsafterward you can audit what the bottom of your ladder currently teachesreasoning

06Reviewing an agent's work is not apprenticeshipafterward you can stop counting review time as training timereasoning

Part 3 — what your numbers are actually measuring

07Your juniors really are producing moreafterward you can state the case against this volume at full strengthsourced

08Why output can rise while capability fallsafterward you can tell the two quantities apart, and say which one you measuresourced

09How to measure unaided capability before you need itafterward you can run the test yourself, in an afternoonreasoning

Part 4 — rebuilding rungs, at a price

10Why rebuilding a rung costs throughput todayafterward you can price the remedy honestly instead of as an investmentreasoning

11The manager who pays is not the one who collectsafterward you can explain why this cannot be delegated downwardreasoning

12Reading four years of a real team's ladderafterward you can say what will be true of your own team in three yearsexhibit

Every term this page uses

apprenticeship: Learning a craft by doing the easy version of it next to somebody doing the hard version, and being corrected.
rung: One step on the path from new hire to senior: a kind of work that teaches what the next step will need.
unaided capability: What somebody can do with no tool helping them. The quantity this volume is about, and the one nothing you currently measure.
deliberate exposure: Giving somebody work a tool could have done faster, on purpose, so that they learn it.
recognition: Being able to tell whether an answer is right. Cheaper to acquire than construction, and not the same thing.
construction: Being able to produce the answer yourself, from nothing. What reviewing does not teach.
throughput: How much work gets shipped in a period. The thing deliberate exposure costs you.
attrition: People leaving. The clock on this problem, because it decides when the seniors you have now run out.
pipeline: The supply of people arriving at each level from the one below it.

Taken as already known, and so not defined here: agent, model, review, headcount, level. That list is a claim about who is reading, and it is printed so it can be argued with.