The compound principle — work that makes future work easier

Compound engineering inverts the usual entropy of software. In traditional
development each feature tends to make the next one harder — more code, more edge
cases, more interdependencies — so teams eventually spend more time fighting the
system than extending it. Compound engineering's governing claim is that each unit
of work should instead make subsequent units easier: a bug fix eliminates a whole
category of future bugs, a solved problem becomes a reusable pattern, and the
codebase grows easier to understand, modify, and trust over time. Students learn
this as the organising idea the rest of the module operationalises, and why it
reframes the engineer's output from code shipped to leverage accumulated.