The subjects in this notebook can look unrelated at first. A financial intermediary, a backend service, and a pedestrian path belong to different worlds. Yet each can be understood by looking at flows, constraints, and the choices available to participants.
Borrow questions carefully
An analogy is a place to begin asking questions. It is not proof that two systems behave the same way. The interesting work starts when you identify both the resemblance and its limits.
Keep writing
Writing is a way of making an explanation specific enough to examine. If an idea only works while it stays vague, putting it into sentences is often the fastest way to discover that.
That is the spirit of these notes: follow a question, make the reasoning visible, and leave enough room to change your mind.