Amazon QA Engineer System Design Questions

Flaky tests can severely affect Amazon's release process. A mechanism to detect and provide insights into flaky tests will be essential for maintaining code quality.
Design a class FlakyTestDetector with the following methods:
- addTestExecution(testName: str, result: bool): None - Adds a result of a test execution to the detector.
- getFlakyTests(): List[str] - Returns a list of tests identified as flaky based on historical results.Example 1:
Input: addTestExecution('LoginTest', true) followed by addTestExecution('LoginTest', false)
Output: ['LoginTest']
Explanation: The test failed inconsistently, marking it as flaky.Constraints:
- Each test name is unique and of length 1 to 100.
- Results can only be true or false.

As Amazon expands its cloud services, verifying performance under high load is critical. An orchestrator must manage multiple load test scenarios efficiently.
Create a class LoadTestOrchestrator with the following methods:
- scheduleLoadTest(testName: str, duration: int): None - Schedule a load test with a specified duration.
- executeTests(): List[Result] - Execute all scheduled load tests and return their results.Example 1:
Input: scheduleLoadTest('API_Load_Test', 300) followed by executeTests()
Output: [Result]
Explanation: All scheduled tests are executed, returning results in a list.Constraints:
- Duration is a positive integer less than or equal to 3600 seconds.

As Amazon continues to expand its automated testing capabilities, it becomes critical to consolidate results from varied testing environments. This requires a robust class design.
Design a class TestResultAggregator with the following methods:
- addResult(testName: str, result: bool): None - Adds a test result for the specified test.
- getSummary(): Dict[str, int] - Returns a summary of passed and failed tests.Example 1:
Input: addResult('LoginTest', true) followed by addResult('SignupTest', false)
Output: {'passed': 1, 'failed': 1}
Explanation: 1 test passed, and 1 test failed.Constraints:
- Test names are unique strings of length 1 to 100.