What Brendan realized
"The entire ratio — units to integration to E2E — is a human-capital ratio. If you take the human cost out of test maintenance, why would you keep the same ratio?"
In an agent-driven world: Writing a test — near zero cost. Maintaining it when code changes — near zero. Generating synthetic data — near zero. Updating a selector when the UI shifts — near zero.
What remains
Compute costs. And engineers who understand what the tests should assert and whether a passing test actually means what you think it means. That judgment is not going anywhere.
What the new shape allows
Every account creation path. Every loan decisioning branch. Every payment edge case — extra payment, missed payment, payoff with a balance dispute. Every report format. Every regulatory variant.
The tests that most closely mirror user behavior. The tests that catch integration failures across domain seams. The tests the pyramid said you couldn't afford.
New shape
Not the pyramid. Not the inverted pyramid. The square — comprehensive coverage at every layer because none of them are prohibitively expensive anymore.