There's a myth that testing slows teams down. In our experience the opposite is true: a suite you trust is exactly what lets you move fast, because you can change things without fear.
Every layer, every change
Domain logic gets unit tests. Endpoints get integration tests against a real database. Critical flows get end-to-end coverage that drives the live system. A change that touches a layer ships with the tests for that layer — not a promise to add them later.
Green isn't the same as done
We've learned that a passing CI run on an empty database can still hide a failure that only appears against real data. So we test against populated states, and we keep the gates that block a PR identical to the gates that verify the main branch. No surprises after merge.
We'd rather move deliberately and ship something that holds up than move fast and find out in production.