Follow a test pyramid: many fast unit tests, fewer integration tests, and a small number of end-to-end tests. For integration, test important seams (DB, messaging) with realistic dependencies (e.g., Testcontainers) and keep them parallelizable and stable. Avoid one giant “tests everything” suite.
Expanding on the short answer — what usually matters in practice:
A tiny example (an explanation template):
// Example: discuss trade-offs for "how-do-you-approach-integration-testing-in-a-mon"
function explain() {
// Start from the core idea:
// Follow a test pyramid: many fast unit tests, fewer integration tests, and a small number o
}