Google DevOps Engineer System Design Questions

In modern cloud architectures, managing application configurations centrally is critical for consistency and flexibility. Design a ConfigManager class that allows applications to store and retrieve configurations using a key-value pair approach.- class ConfigManager:
- def set_config(self, key: str, value: str) -> None:
Store a configuration value with the associated key.
- def get_config(self, key: str) -> str:
Retrieve the configuration value for the specified key.
- def delete_config(self, key: str) -> None:
Remove the configuration entry.
- def list_configs(self) -> List[Tuple[str, str]]:
Return a list of all configurations as key-value pairs.Example 1:
Input: config_manager = ConfigManager()
config_manager.set_config('feature_x_enabled', 'true')
Output: None
Explanation: Configuration is stored successfully.Constraints:
- 1 <= key.length <= 100
- 1 <= value.length <= 100
- Total number of configurations will not exceed 1000.

In microservices architecture, a Circuit Breaker pattern is used to prevent an application from repeatedly trying to execute operations that are likely to fail. Design a CircuitBreaker class that manages the state of the circuit breaker and the logic to handle requests based on its state.- class CircuitBreaker:
- def call(self, request: Callable[[], T]) -> T:
Executes a request and returns the result or raises an exception if the circuit is open.
- def reset(self) -> None:
Resets the circuit breaker state.Example 1:
Input: cb = CircuitBreaker()
result = cb.call(lambda: my_service_call())
Output: result from my_service_call() or raises an exception
Explanation: The method either returns the result of the service call or throws an exception if the circuit is open.Constraints:
- The circuit contains a specified timeout and threshold for failures.

In order to ensure continuous integration and delivery, it is necessary to design a CI/CD pipeline that automates testing and deployment for various Google services in a scalable manner.
Implement a class CICDPipeline that manages builds and deployments, handles test executions, and keeps track of build histories.- class CICDPipeline:
- def build(self, service_name: str) -> bool:
Returns True if the build is successful, otherwise False.
- def test(self, service_name: str) -> bool:
Returns True if the tests are successful, otherwise False.
- def deploy(self, service_name: str) -> bool:
Returns True if deployment is successful, otherwise False.
- def get_build_history(self) -> List[str]:
Returns a list of build history.Example 1:
Input: pipeline = CICDPipeline()
pipeline.build('ServiceA')
Output: True
Explanation: The build for ServiceA was successful.Constraints:
- 1 <= service_name.length <= 100
- Number of services managed by the pipeline will not exceed 1000.