Peizhao Zhao focused on stabilizing the Spanner-related test suite in the GoogleCloudPlatform/spring-cloud-gcp repository, addressing reliability issues in continuous integration. By replacing brittle exact-match assertions with regex and partial matches, Peizhao ensured that tests verified intended exception behavior rather than relying on specific error message formatting. This approach targeted flaky tests such as SpannerPersistentPropertyImplTests and ConverterAwareMappingSpannerEntityReaderTests, reducing false negatives and improving maintainability. Working primarily with Java and the Spring Framework, Peizhao applied test-driven development and unit testing principles to accelerate release readiness and enhance CI feedback cycles, demonstrating depth in diagnosing and resolving complex test stability challenges.