Search a Job Board for the Thing You Learned in 2019

Take the framework you learned properly in 2019. The one you were good at, the one that got you the job.

Open a job board and search for it.

That is the whole problem in its smallest form, and every technologist has had this experience at least once. It is not a career-ending event. You re-skilled, it was fine, you are employable. But notice what actually happened: a large amount of expensive, hard-won knowledge quietly went to approximately zero, and nothing you built during those years survived the transition except your general competence and your contacts.

No other profession does this. An accountant's knowledge from 2015 is mostly still good. A surgeon's technique improves rather than expires. Yours has a half-life, and you have been paying it for your entire career without ever charging anyone for the part that was about to expire.

So the question is not whether you know something worth teaching. It is which of the things you know is decaying fastest, because that determines everything about how you should build.

Where does your knowledge actually sit?

Four positions. Find yours.

You are deep in something currently hot. The audience is enormous and the window is short — two or three years before the material needs rebuilding, and a lot of competition arriving at the same time.

Build here, but build knowing what you are buying. The course is short-lived. The audience it earns you is not. Treat the hot topic as the thing that gets you found, not as the business, and get people onto a list you own before the wave moves.

You are deep in something mature or unfashionable. The stack that runs a bank, a mainframe process, an old ERP, a version everybody is stuck on and nobody advertises.

This is the strongest position in the entire profession, and people apologize for it. The audience is smaller, and it is also desperate, well-funded, and served by nobody. The material barely changes, so a course you build now is still accurate in five years. And there is no competing content, because nobody enthusiastic enough to make content is working on it.

If you are here, stop treating it as a thing to escape and start treating it as inventory.

You are a generalist, architect or staff engineer. What you actually know is which trade-offs matter, in what order, and what breaks at what scale.

This does not expire at all — the specifics change and the shape of the judgment does not. It is also the hardest to package, because it does not decompose into a syllabus. The route in is to teach one recurring decision at a time, through real cases: here is the situation, here are the three options, here is what actually happens with each, here is what I would pick and what would change my mind.

You have moved into management or you are about to. Then the sellable knowledge is the transition itself.

There are a great many technically excellent people about to make that move badly, with no honest account available to them of what changes, what they will miss, and what the first six months feel like. You are two years past it and you remember precisely.

What all four have in common

Whichever branch you are on, the same mechanism applies, and it is what makes the depreciation problem survivable.

You publish consistently. That builds an audience. The audience tells you, in questions and complaints, what they are struggling with — which becomes the next thing you write, and eventually the next product. Those products bring in more people, who tell you more. The loop runs and it compounds.

Now notice what is inside that loop and what is not. The course content is not — it is the perishable part. The audience, the list, the reputation for being the person who explains this clearly: none of that is attached to a version number. When your stack turns over, you rebuild the product and keep the market.

That is the exact inverse of your employment situation, where the skill turns over and you keep nothing.

The mistake you will make

You will want to teach the newest thing, because it is the most interesting and you have just learned it.

The newest thing has the largest audience of people who are not yet paying for anything. Enthusiasm is not a budget. The money is with people who have a problem now, on a system that is already in production, with a deadline attached to it.

So test whichever branch you picked against one question: does someone lose money, time, or a job because of this problem today? If the answer involves the word "eventually," you have chosen the exciting topic rather than the real one.

The framework you searched for is not coming back. The next one will go the same way. The only thing you can build in this profession that does not have a version number is a group of people who know your name and read what you write.