Don't try to stand up everything. Combine fast unit tests, narrow integration tests against real dependencies started in disposable containers (Testcontainers), fakes for third-party services, and contract tests between service pairs. Fowler's guide recommends testing one integration point at a time with test doubles, then running contract tests against both the double and the real service so the double stays faithful. Testcontainers gives each test run its own isolated database or broker, which avoids the shared-state flakiness of common staging environments and lets tests run in parallel. Keep true end-to-end tests to a few critical user journeys.

For HTTP dependencies in lighter tests, an interception tool such as Mock Service Worker (MSW) or Pact's mock server can return prepared responses inside the test process, without opening a network connection.

Sources: Fowler, Docker blog on Testcontainers, Pact docs