Not sure if you've read the article, but with benefit of doubt:

>What the fuck does "manage 1 person" mean?

"Manage one person" is relatively self-explanatory. On the org chart, you are designated as a team lead, with exactly one (1) person reporting to you. You are responsible for their work, career, and success. They have you as their boss.

It is relatively common in many organizations, including tech/software, due to (likely mistaken) belief that it will ease in a new manager/team-lead. Alternatively it could be circumstantial due to people leaving or weird teams forming or planned expansion that doesn't happen or difficulty hiring, or a natural hierarchy of a very senior and very junior developer, etc.

>>do some work yourself.

Typically, a manager or team lead of small teams absolutely does do some of their work themselves. In fact, usually they do ALL their usual work, AND now coach/guide/manage their team, in this case a single person. Usually the situation is the antithesis of "free loading".

Given such situations absolutely do occur, the post seems to be fairly realistic as to common ways they can go wrong, and how to address them.