Uber QA Engineer System Design Questions

As Uber scales its testing infrastructure, it's essential to have a robust mechanism that can efficiently aggregate results from various automated tests, analyze performance, and report statistics.
Your challenge is to design a TestResultAggregator class that consolidates test results.
- Method 1: void addResult(TestResult result) — Accepts a test result and adds it to the internal storage.
- Method 2: Statistics getStatistics() — Returns aggregated statistics (e.g., pass rate, average execution time).Example 1:
Input: addResult(testResult)
Output: void
Explanation: The result is stored in the aggregator.Example 2:
Input: getStatistics()
Output: Statistics
Explanation: Returns the aggregated statistics from previously added results.Constraints:
- The number of test results will not exceed 10000.

As Uber's service scales globally, efficient caching mechanisms become essential for optimizing API performance and reducing latency. Your challenge is to implement an LRU Cache to handle frequently accessed API responses.
- Method 1: void put(String key, Value value) — Stores a value in the cache with the associated key.
- Method 2: Value get(String key) — Retrieves the value for the key and refreshes its access order.Example 1:
Input: put('user_1', data)
Output: void
Explanation: The data for user_1 is stored in the cache.Example 2:
Input: get('user_1')
Output: data
Explanation: The function returns the cached data for user_1.Constraints:
- The capacity of the cache is defined as N, with a maximum value of 1000.