Engineering Atlas — The Ten Properties of Software Quality

The Engineering Atlas guide opens with a reframe: stop asking whether a system is good and start asking which property it is missing, because "good" is not a property. It then walks ten properties — Correctness, Reliability, Performance, Scalability, Security, Maintainability, Operability, Usability, Cost, and Compliance — each with its own decades-old body of practice. The fetched portion covers that framing plus the full first chapter, Correctness.

Correctness is "getting the right answer": the system computes correctly and keeps the promises it made about its own state. The chapter's through-line is Dijkstra's observation that testing shows the presence of bugs, never their absence — read not as despair but as a design constraint. Since you cannot check every input and interleaving, correctness is built in layers: requirements that say what "right" means, designs that make wrong states hard to reach, and tests that pin behaviour so it can't drift.

The lane runs from the keyboard to the distributed system. Core practices: whole-team quality, the testing pyramid, trunk-based development, ubiquitous language, TDD, property-based testing, and mutation testing (the chapter's single recommendation: measure your tests with mutation testing). The strongest move is designing wrong states out of existence — Make Illegal States Unrepresentable — so a whole family of tests is never needed. At the distributed edge, correctness becomes an agreement problem: consistency models, contract testing, data contracts, and the transactional outbox for publishing an event without letting a crash split it from the state change.

The recurring trap is trusting the green checkmark: a passing suite proves only the behaviours you thought to check, and coverage targets make this worse — a suite can be 90 percent covered and nearly toothless. The pattern across the chapter is that correctness is earned in small installments, and the highest-value work removes the possibility of a bug rather than hunting for its absence.