How do you speed up slow integration tests without compromising quality?

Tests your ability to balance speed and safety in CI/CD test architecture. A strong answer proposes four strategies in order: first, parallelize test execution across multiple runners; second, apply Test Impact Analysis to run only tests affected by code changes; third, use containerized ephemeral environments with tools like Testcontainers to eliminate shared-state flakiness; and fourth, manage test data as code for fast, repeatable setup.